Class 10

Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication

You can Download Samacheer Kalvi 10th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication

Samacheer Kalvi 10th Science Visual Communication Textual Evaluation Solved

I. Choose the correct answer:

Question 1.
Which software is used to create animation?
(a) Paint
(b) PDF
(c) MS Word
(d) Scratch.
Answer:
(d) Scratch.

Question 2.
All files are stored in the:
(a) Folder
(b) box
(c) Pai
(d) Scanner
Answer:
(a) Folder

Question 3.
Which is used to build scripts?
(a) Script area
(b) Block palette
(c) Stage
(d) Sprite.
Answer:
(a) Script area

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Question 4.
Which is used to edit programs?
(a) Inkscape
(b) Script editor
(c) Stage
(d) Sprite
Answer:
(b) Script editor

Question 5.
Where you will create the category of blocks?
(a) Block palette
(b) Block menu
(c) Script area
(d) Sprite.
Answer:
(b) Block menu

II. Match the following:

Question 1.

1. Script Area (a) Type notes
2. Folder (b) Animation software
3. Scratch (c) Edit programs
4. Costume editor (d) Store files
5. Notepad (e) Build Scripts

Answer:

  1. (e) Build Scripts
  2. (d) Store files
  3. (b) Animation software
  4. (c) Edit programs
  5. (a) Type notes.

III. Answer the following:

Question 1.
What is Scratch?
Answer:
‘Scratch’ is a software used to create animations, cartoons and games easily. Scratch, on the other hand, is a visual programming language. It was developed in the Massachusetts Institute of Technology (MIT) Media Lab to make programming easier and more fun to learn.

Question 2.
Write a short note on editor and its type?
Answer:
There are two types of editors. They are (i) Script editor (ii) Costume editor.
Editors are used to edit your programs or your sprite’s pictures. The script editor has three main parts: Script area, Block menu and Block palette. When costume editor tab is chosen, Click → File / New to create new project.

Question 3.
What is Stage?
Answer:
The stage is the background appearing when we open the scratch window. The background will most often be white. You can change the background colour as you like.

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Question 4.
What is Sprite?
Answer:
The characters on the background of a scratch window are known as sprite. Usually a cat appears as a sprite when the scratch window is opened. The software provides facilities to make alternations in sprite.

Samacheer Kalvi 10th Science Visual Communication Additional Questions Solved

I. Choose the correct answer.

Question 1.
The characters on the background of a scratch window are known as _______.
(a) stage
(b) screen
(c) sprite
(d) script.
Answer:
(c) sprite

Question 2.
Which button is click, it shows the list of all programs in the computer?
(a) My computer
(b) START
(c) Recycle Bin
(d) Explorer
Answer:
(b) START

Question 3.
Choose the correct pair for the following _______.
(a) Stage – bottom left
(b) Sprite list – top left
(c) Script tab – right
(d) None of these.
Answer:
(c) Script tab – right

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Question 4.
The device which helps in explaining the concepts easily through pictures is known as:
(a) Visual communication device
(b) Paint
(c) Notepad
(d) Scratch
Answer:
(a) Visual communication device

Question 5.
Choose the correct statement from the following _______.
(a) The output we get from any application is called folder.
(b) Cinema is a good example of VCD.
(c) The characters on the background of a scratch window are known as a stage.
(d) The scratch editor has four main parts.
Answer:
(b) Cinema is a good example of VCD.

Question 6.
Which company was developed by Scratch software?
(a) Massachusetts Institute of Technology (MIT)
(b) Microsoft corporation
(c) Sun micro system
(d) Oracle corporation
Answer:
(a) Massachusetts Institute of Technology (MIT)

Question 7.
The output we get from any application is commonly referred to as _______.
(a) file
(b) folder
(c) hardware
(d) software.
Answer:
(a) file

Question 8.
Choose the correct pair:
(a) Script – Event
(b) Mouse – Output
(c) Visual – blackboard
(d) NEW – Start
Answer:
(a) Script – Event

Question 9.
When we _____ on the mouse, the popup menu appears.
(a) right – click
(b) left click
(c) click
(d) right.
Answer:
(a) right-click

Question 10.
Choose the correct statement:
(a) The scratch editor has two main parts.
(b) The stage background will most often be black.
(c) Block menu, where you build scripts
(d) The script editor right pane also contains two additional tabs, costumes and sounds.
Answer:
(d) The script editor right pane also contains two additional tabs, costumes and sounds.

Question 11.
The list of all programs loaded in the computer is shown when you click _______ button.
(a) Home
(b) list
(c) All programs
(d) start.
Answer:
(d) start.

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Question 12.
Which device helps in explaining the concepts easily through pictures?
(a) Audiometer
(b) Video meter
(c) Visual audio device
(d) Visual communication device.
Answer:
(d) Visual communication device.

Question 13.
Which one of the following is a good example of a visual communication device?
(a) Theatre
(b) Cinema
(c) Exhibitions
(d) poster making.
Answer:
(b) Cinema

Question 14.
VCD means _______.
(a) Virtual compact disk
(b) Video compact disc
(c) Visual contract device
(d) Visual communication device.
Answer:
(d) Visual communication device.

Question 15.
Which one of the following is a visual programming language?
(a) Visual Basic
(b) Scratch
(c) Visual C++
(d) paint.
Answer:
(b) Scratch

Question 16.
Expand MIT _______.
(a) Maritime Institute of Technology
(b) Madras Institute of Technology
(c) Massachusetts Institute of Technology
(d) Maldives Institute of Technology.
Answer:
(c) Massachusetts Institute of Technology

Question 17.
The Scratch editors consists of ______ main parts.
(a) 2
(b) 3
(c) 4
(d) 5.
Answer:
(b) 3

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Question 18.
Pick the odd one out _______.
(a) Stage
(b) Screen
(c) Sprite
(d) Script editor.
Answer:
(b) Screen

Question 19.
_______ is the background appearing when we open the scratch Window.
(a) Stage
(b) Screen
(c) Sprite
(d) Script.
Answer:
(a) Stage

Question 20.
What is the default colour of the stage?
(a) red
(b) yellow
(c) white
(d) black.
Answer:
(c) white

Question 21.
Find the correct statement from the following?
(a) The background colour of the stage can be changed.
(b) The background colour of the stage cannot be changed.
Answer:
(a) The background colour of the stage can be changed.

Question 23.
The _____ pane also contains two additional tabs like costumes and sounds.
(a) left
(b) right
(c) centre
(d) bottom.
Answer:
(b) right

Question 24.
Find the false statement from the following.
(a) When the costume tab is chosen, the costume editor appears in red colour.
(b) When the costume tab is chosen, the costume editor appears in blue colour.
Answer:
(b) When the costume tab is chosen, the costume editor appears in blue colour.

Question 25.
What is the command used to create a new project?
(a) File →New
(b) File → project New
(c) File → New project
(d) File → project.
Answer:
(a) File → New

Question 26.
Click the _____ flag at the top right comer of the stage to run your program.
(a) red
(b) blue
(c) green
(d) yellow.
Answer:
(c) green

Question 27.
Which is not a part of script editor?
(a) sprite
(b) script area
(c) Block menu
(d) Block palette.
Answer:
(a) sprite

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Question 28.
Click the scripts tab and find the play sound block from the ________ menu.
(a) scripts
(b) events
(c) sound
(d) audio.
Answer:
(c) sound

II. Match the following:

Question 1.

1. VCD (a) Storage space
2. File (b) Cinema
3. Folder (c) Software
4. Scratch (d) Specific purpose

Answer:

  1. (b) Cinema
  2. (d) Specific purpose
  3. (a) Storage space
  4. (c) Software.

Question 2.

1. Script tabs (a) Unknown place
2. Build scripts (b) Blocks tab
3. Right pane (c) Script area
4. Guide board (d) Costumes and sounds

Answer:

  1. (b) Blocks tab
  2. (c) Script area
  3. (d) Costumes and sounds
  4. (a) Unknown place.

III. Fill in the blanks:

Question 1.
______ and ____ plays a vital role in the working of the computer.
Answer:
Software, hardware.

Question 2.
In Windows OS, ______ application is used to draw pictures.
Answer:
paint.

Question 3.
In Windows OS, we can collect our notes in ______ application.
Answer:
Notepad.

Question 4.
The ______ tab on the right contains the blocks tabs and scripts area.
Answer:
Scripts.

Question 5.
Click the menu _____ drag a when green flag clicked the block to the scripts area.
Answer:
Script → Event.

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Question 6.
Sound is present in _____ option.
Answer:
Script.

Question 7.
Visual programming was developed in the _______.
Answer:
Massachusetts Institute of Technology (MIT).

IV. Short Answer Questions

Question 1.
Define file.
Answer:
The output we get from any application is commonly referred to as ‘file’. Therefore the application for the specific purposes determines the nature of the file.

Question 2.
How can we save data and information in computer?
Answer:
We can save data and information in folders which accommodate a single file or multiple files. So all files are stored in the folder.

Question 3.
Define VCD. (Visual Communication Device)?
Answer:
The device which helps in explaining the concepts easily through pictures is known as ‘Visual Communication Device’. For example photos, audiovisuals, drawings, animations all these can be created easily with the help of the computer. Cinema is a good example of ‘Visual Communication Device’.

Question 4.
Write any four operating systems?
Answer:

  1. Windows
  2. UNIX
  3. LINUX
  4. iOS.

Question 5.
What are the three main parts of the script editor?
Answer:
The script editor has three main parts:

  • Script area: Where you build scripts.
  • Block menu: Where you choose the category of blocks (programming statements) to use.
  • Block palette: Where you choose the block to use.

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Question 6.
How will you add sound using the costume tab?
Answer:
When the Costumes tab is chosen, the costume editor, Click File/New to create a new project and enter a project name.
Click File / New to create a new project and enter a project name.

Adding Sound:

  1. Click Spritel in the sprite list and click the Sounds tab.
  2. Try the meow sound already there. If you don’t like it, click the speaker icon to choose a different sound from the sound library.
  3. Click the Scripts tab and find the play sound block from the Sound menu. Add this block to the when space key pressed script. (Select the sound you want from the drop-down list.)
  4. Run your program.

Question 7.
Explain how will you create a new project?
Answer:
Click File / New to create a new project and enter a project name.

V. Long Answer Questions

Question 1.
Explain adding sound with an example.
Answer:
Adding Sound:

  1. Click Spritel in the sprite list and click the Sounds tab.
  2. Try the meow sound already there. If you don’t like it, click the speaker icon to choose a different sound from the sound library.
  3. Click the Scripts tab and find the play sound block from the Sound menu. Add this block when space key pressed script. (Select the sound you want from the drop-down list.)
  4. Run your program.

Example:
Program for print the word “Hello” with sound:
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 1

1. Click events in script option.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 2

2. Drag “When Clicked” tab to script area.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 3

3. Click Looks in script option. Drag “say” to script area.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 4

4. Type “Hello “ word in say tab.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 5

5. Click sounds in script option. Drag play sound to script area. Choose the hello sound from the audio file.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 6

6. From File menu choose the Save option.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 7

7. Click the green flag at the top right comer of the stage window to run the program.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 8

Question 2.
Explain how will you give movements and loops. Give an example.
Answer:
Click the menu Script → Event, drag a when green flag clicked a block to the scripts area. Your scripts area should look like this:
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 9
Click the menu Script → Motion menu, drag a goto x : 0, y : 0 blocks to the scripts area and snap it to the bottom of the when green flag clicked the block.
Your script should look like this:
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 10
Add a move 10 steps block to the bottom of your script and change the 10 into 100.
Samacheer Kalvi 10th Science Solutions Chapter 23 Visual Communication 11
Click the green flag at the top right comer of the stage to run your program.

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Samacheer Kalvi 10th Science Solutions Chapter 21 Health and Diseases

You can Download Samacheer Kalvi 10th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 21 Health and Diseases

Samacheer Kalvi 10th Science Health and Diseases Textual Evaluation Solved

I. Choose the Correct Answer.

Question 1.
Tobacco consumption is known to stimulate the secretion of adrenaline. The component causing this could be _______.
(a) Nicotine
(b) Tannic acid
(c) Curcumin
(d) Leptin.
Answer:
(a) Nicotine

Question 2.
World ‘No Tobacco Day’ is observed on:
(a) May 31
(b) June 6
(c) April 22
(d) October 2
Answer:
(a) May 31

Question 3.
Cancer cells are more easily damaged by radiations than normal cells because they are _______.
(a) Different in structure
(b) Non-dividing
(c) Mutated Cells
(d) Undergoing rapid division.
Answer:
(d) Undergoing rapid division.

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Question 4.
Which type of cancer affects lymph nodes and spleen?
(a) Carcinoma
(b) Sarcoma
(c) Leukemia
(d) Lymphoma
Answer:
(c) Leukemia

Question 5.
Excessive consumption of alcohol leads to _______.
(a) Loss of memory
(b) Cirrhosis of liver
(c) State of hallucination
(d) Suppression of brain function.
Answer:
(b) Cirrhosis of liver

Question 6.
Coronary heart disease is due to:
(a) Streptococci bacteria
(b) Inflammation of pericardium
(c) Weakening of heart valves
(d) Insufficient blood supply to heart muscles
Answer:
(d) Insufficient blood supply to heart muscles

Question 7.
Cancer of the epithelial cells is called _______.
(a) Leukaemia
(b) Sarcoma
(c) Carcinoma
(d) Lipoma.
Answer:
(c) Carcinoma

Question 8.
Metastasis is associated with:
(a) Malignant tumour
(b) Benign tumour
(c) Both (a) and (b)
(d) Crown gall tumour
Answer:
(a) Malignant tumour

Question 9.
Polyphagia is a condition seen in _______.
(a) Obesity
(b) Diabetes mellitus
(c) Diabetes insipidus
(d) AIDS.
Answer:
(b) Diabetes mellitus

Question 10.
Where does alcohol effect immediately after drinking?
(a) Eyes
(b) Auditory region
(c) Liver
(d) Central Nervous System
Answer:
(d) Central Nervous System

II. State whether True or False. If false, write the correct statement:

Question 1.
AIDS is an epidemic disease.
Answer:
False.
Correct Statement: AIDS is a viral disease.

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Question 2.
Cancer-causing genes are called Oncogenes.
Answer:
True.

Question 3.
Obesity is characterized by tumour formation.
Answer:
False.
Correct Statement: Obesity is characterized by an accumulation of excess body fat with an abnormal increase in body weight.

Question 4.
In leukaemia, both WBCs and RBCs increase in number.
Answer:
False.
Correct Statement: Leukemia is characterized by an increase in the formation of white blood cells in the bone marrow and lymph nodes.

Question 5.
Study of the cause of the disease is called aetiology.
Answer:
False.
Correct Statement: Study of a cause of the disease is called Pathology.

Question 6.
AIDS is not transmitted by contact with a patient’s clothes.
Answer:
True.

Question 7.
Type 2 diabetes mellitus results due to insulin deficiency.
Answer:
False.
Correct Statement: In type 2 diabetes mellitus, Insulin production by the Pancreas is normal, but the target cells do not respond to insulin.

Question 8.
Carcinogens are cancer-causing agents.
Answer:
True.

Question 9.
Nicotine is a narcotic drug.
Answer:
False.
Correct Statement: Nicotine is a stimulant, highly harmful and poisonous substance, in Tobacco.

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Question 10.
Cirrhosis is associated with the brain disorder.
Answer:
False.
Correct Statement: Liver damage resulting in Fatty liver which leads to Cirrhosis and formation of fibrous tissues.

III. Expand the following abbreviations:

Question 1.

  1. IDDM
  2. HIV
  3. BMI
  4. AIDS
  5. CHD
  6. NIDDM.

Answer:

  1. Insulin Dependent Diabetes Mellitus
  2. Human Immunodeficiency Vims
  3. Body Mass Index
  4. Acquired Immuno Deficiency Syndrome
  5. Coronary Heart Disease
  6. Non – Insulin Dependent Diabetes Mellitus.

IV. Match the following:

Question 1.

1. Sarcoma (a) Stomach cancer
2. Carcinoma (b) Excessive thirst
3. Polydipsia (c) Excessive hunger
4. Polyphagia (d) Lack of blood flow to the heart muscle
5. Myocardial Infarction (e) Connective tissue cancer

Answer:

  1. (e) Connective tissue cancer
  2. (a) Stomach cancer
  3. (b) Excessive thirst
  4. (c) Excessive hunger
  5. (d) Lack of blood flow to the heart muscle.

V. Fill in the blanks:

Question 1.
Cirrhosis is caused in the liver due to excessive use of _______.
Answer:
Alcohol.

Question 2.
A highly poisonous chemical derived from tobacco is _______.
Answer:
Nicotine.

Question 3.
Blood cancer is called _______.
Answer:
Leukaemia.

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Question 4.
Less response of a drug to a specific dose with repeated use is called _______.
Answer:
Tolerance.

Question 5.
Insulin resistance is a condition in _______ diabetes mellitus.
Answer:
Type – 2.

VI. Analogy Type Questions.

Identify the first words and their relationship and suggest a suitable word for the fourth blank:

Question 1.
Communicable : AIDS :: Non – communicable : _______.
Answer:
Obesity.

Question 2.
Chemotherapy : Chemicals :: Radiation therapy : _______.
Answer:
Radiation.

Question 3.
Hypertension : Hypercholesterolemia :: Glycosuria : _______.
Answer:
Polyphagia.

VII. Answer in a Sentence.

Question 1.
What are psychotropic drugs?
Answer:
The drugs which act on the brain and alter the behaviour, consciousness, power of thinking and perception, are called Psychotropic drags. They are also called Mood altering drugs.

Question 2.
Mention the diseases caused by tobacco smoke.
Answer:
Bronchitis, pulmonary tuberculosis, emphysema hypoxia, lung cancer, hypertension gastric and duodenal ulcer are diseases caused be tobacco smoke.

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Question 3.
What are the contributing factors for obesity?
Answer:
Obesity is due to genetic factors, physical inactivity, overeating and endocrine factors.

Question 4.
What is adult onset diabetes?
Answer:
Type-2 Non Insulin Dependent Diabetes Mellitus (NIDDM) is called as adult onset diabetes.

Question 5.
What is metastasis?
Answer:
The Cancerous cells migrate to distant parts of the body and affect new tissues and this process is called Metastasis.

Question 6.
How does insulin deficiency occur?
Answer:
Insulin deficiency occur due to the destruction of B – cells of the pancreas, characterized by abnormally elevated blood glucose level resulting from inadequate insulin secretion.

VIII. Short Answer Questions

Question 1.
What are the various routes by which transmission of human immunodeficiency virus takes place?
Answer:
HIV is transmitted generally by:

  1. Sexual contact with infected person
  2. Use of contaminated needles or syringes especially in case of intravenous drag abusers
  3. By transfusion of contaminated / infected blood or blood products (iv) From infected mother to her child through placenta.

Question 2.
How is a cancer cell different from a normal cell?
Answer:
Cancer is an abnormal and uncontrolled division of cells that invade and destroy the surrounding tissue, forming a tumour or neoplasm. It is a heterogeneous group of cells, that do not respond to the normal cell division. The cancer cells move to distant parts of bodies such as lungs, bones, liver, skin and brain.

Question 3.
Differentiate between Type-1 and Type-2 diabetes mellitus.
Answer:

Type-1 Diabetes mellitus Type-2 Diabetes mellitus
1. People with type – 1 diabetes do not produce insulin in the pancreas. 1. People with type – 2 diabetes do not respond to insulin.
2. the immune system destroys insulin – producing beta cells in the pancreas. 2. People with type – 2 diabetes are Insulin Resistant. The body produces insulin but unable to use effectively.
3. Cannot be controlled without taking insulin. 3. Possible to treat initially without medication or treating with tablets.

Question 4.
Why is a dietary restriction recommended for an obese individual?
Answer:
Obesity has a positive risk factor in development of hypertension, diabetes, gall bladder disease, coronary heart disease and arthritis. To avoid the dietary restriction is recommended for an obese individual.

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Question 5.
What precautions can be taken for preventing heart diseases?
Answer:
Diet Management: Reduction in the intake of calories, low saturated fat and cholesterol – rich food, low carbohydrates and common salt are some of the Dietary modifications. Diet rich in polyunsaturated fatty acids is essential. Increase in the intake of fibre diet, fruits and vegetables, protein, minerals and vitamins are needed.

  • Physical activity: Regular exercise, walking and yoga are essential for bodyweight maintenance.
  • Avoid Addictive substances: Alcohol consumption, Psychotropic drugs and smoking are to be avoided.

IX. Long Answer Questions

Question 1.
Suggest measures to overcome the problems of an alcoholic.
Answer:
Education and counselling: Education and proper counselling will help the alcoholics to overcome their problems and stress, to accept failures in their life.
Physical activity : Individuals undergoing rehabilitation should be channelized into healthy activities like reading, music, sports, yoga and meditation.

Seeking help from parents and peer groups : When a problematic situation occurs, the affected individuals should seek help and guidance from parents and peers. This would help them to share their feeling of anxiety, wrong dping and get rid of the habit.

Medical assistance : Individual should seek help from psychologists and psychiatrists to get relieved from this condition and to lead a relaxed and peaceful life.

Alcohol de-addiction and rehabilitation programmes are helpful to the individual so that they could get rid of the problem completely and can lead a normal and healthy life.

Question 2.
Changes in lifestyle is a risk factor for the occurrence of cardiovascular diseases. Can it be modified? If yes, suggest measures for prevention.
Answer:
The lifestyle can be modified to prevent cardiovascular diseases. These are the measures for prevention:

  • Do not smoke or use Tobacco.
  • Do Exercise for about 30 minutes.
  • Eat a heart-healthy diet.
  • Reduce the intake of calories, low saturated fat and cholesterol, low carbohydrates and common salt are some of the dietary modifications.
  • Diet rich in polyunsaturated fatty acids (PUFA) is essential.
  • Increase in the intake of fibre diet, fruits and vegetables, protein, minerals and vitamins are essential.
  • Maintain a healthy weight.
  • Get enough quality sleep.
  • Manage stress.
  • Get regular health screens.
  • Control Blood pressure.
  • Keep the cholesterol and triglyceride levels under control.

X. Higher Order Thinking Skills (HOTS) Questions

Question 1.
What is the role of fat in the cause of atherosclerosis?
Answer:
The deposition of cholesterol in the blood vessels gradually develops from which form a fatty streak called plaque. This blocks the pathway of blood flow by narrowing the blood vessels leading to atherosclerosis.

Question 2.
Eating junk food and consuming soft drinks results in health problems like obesity, still, children prefer. What are the suggestions you would give to avoid children eating junk food / consumption of soft drinks?
Answer:
Suggestions, to avoid children, eating Junk food / consumption of soft drinks.

  • Carry a water bottle and drink water.
  • Instead of soft drinks, drink fruit juices, sports drinks or energy drinks.
  • Base meals around protein, legumes, chickpeas, kidney beans and nuts, etc.
  • Avoid getting extremely hungry.
  • Fight stress.
  • Practice mindful eating.
  • Have a piece of fruit, yoghurt, or some crackers.

Question 3.
Regular physical exercise is advisable for normal functioning of the human body. What are the advantages of practising exercise in daily life?
Answer:

  1. Physical exercises help us to live longer and prevent many chronic diseases.
  2. It improves cardiorespiratory and muscular fitness.
  3. It reduces stress, anxiety and depression and improves our mood.
  4. Improves sleep quality and overall quality of life.

Question 4.
A leading weekly magazine has recently published a survey analysis which says that a number of AIDS patient in the country is increasing day by day. The report says that the awareness among the people about AIDS is still very poor. You are discussing the magazine report in your class and a team of your class decides to help people to fight against the dreadful disease.
(a) What problem do you face when trying to educate the people in your village near your school?
(b) How do you overcome the problem?
Answer:
(a) The main problem, we face, is as follows:

  • AIDS patients find it difficult to accept the news.
  • Many people are afraid of telling others because they feel ashamed or they are worried about being rejected.
  • AIDS patients are really discouraged with anxiety about their future.

(b)

  • Confirm the disease by Western Blot Analysis or ELISA.
  • Antiretroviral drugs and immunostimulating therapy can prolong the life of the infected person.
  • Do not tell anyone about our friend’s HIV.
  • Be there to talk to them.
  • Do things together that can reduce stress. Go for a walk. Do something that we enjoy with our AIDS patient friend.
  • Advice the patient friend to avoid activities that have bad health effects like smoking.
  • Patients with HIV / AIDS should not be isolated from the family and society.

XI. Value-Based Questions

Question 1.
Once a person starts taking drugs or alcohol it is difficult to get rid of the habit. Why?
Answer:
The addictive potential of the drugs pulls the individual into a viscous cycle leading to regular abuse and depending. Moreover, some drugs act in the brain and alter the behaviour, consciousness, power of thinking and perception.

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Question 2.
Men addicted to tobacco lead to oxygen deficiency in their body. What could be the possible reason?
Answer:
Carbon monoxide of tobacco smoke binds to the haemoglobin of RBC and decreases its oxygen-carrying capacity causing hypoxia in body tissues.

Question 3.
Name any three foods that are to be avoided and included in the diet of a diabetic patient. Why should it be followed?
Answer:
Refined sugar, carbohydrates rich food and high fat content rich foods should be avoided.
Low carbohydrate and fibre rich diet. Diet comprising whole grains, millet, green leafy vegetables should be included in the diet.

Question 4.
How can informational efforts change people’s HIV knowledge and behaviour?
Answer:

  • Find the latest information about viral suppression and Viral Load Monitoring.
  • Find the latest prevention and how to talk with patients with HIV about, what it means for them.
  • Learn how HIV care providers, can identify and address mental health and substance use disorders to help patients, adhere to HIV treatment and remain in care.

XII. Assertion and Reasoning Questions

In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of statements given below mark the correct answer as
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion Mid Reason is true that Reason is not the correct explanation of Assertion.
(c) The assertion is true but Reason is false.
(d) Both Assertion and Reason are false.

Question 1.
Assertion: All drugs act on the brain.
Reason: Drugs disturb the functioning of the body and mind.
Answer:
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Question 2.
Assertion: Excretion of excess glucose in the urine is observed in a person with diabetes mellitus.
Reason: Pancreas is unable to produce sufficient quantity of insulin.
Answer:
(b) If both Assertion and Reason are true that Reason is not the correct explanation of Assertion.

Textbook Activities Solved

Question 1.
Collect pictures of people affected by tobacco chewing and tobacco smoking. Identify which part of the body is affected and the health hazards it can lead to?
Answer:
The students should collect pictures of people affected by Tobacco Chewing and Tobacco smoking.
Health Hazards: Affected part is mouth on Tobacco Chewing. Chewing Tobacco causes mouth cancer, throat cancer, soreness, gum diseases, tooth decay, tooth loss, possible links to other cancer and Cardiovascular diseases.

Tobacco smoking causes Lung diseases causing damaging alveoli, emphysema, chronic bronchitis, cough, cold, wheezing, asthma, pneumonia and lung cancer. It also affects the central nervous system, increases blood pressure and heartbeat. It also damages DNA.

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Question 2.
Collect pictures of individuals with normal liver and alcoholic liver, compare and indicate the changes you find in them.
Answer:

  • The students should collect pictures of normal liver and alcoholic liver.
  • Normal liver: Under normal circumstances, the normal liver is smooth with no irregularities. The enzymes mostly reside within the cells of the liver.

Fatty liver disease occurs as a result of alcohol drinking, which leads to cirrhosis and formation of fibrous tissues, which replaces the normal liver tissue.

Question 3.
Prepare a chart showing the food items which are preferable and which should be avoided to prevent high blood pressure and heart disease. Apart from diet what are the other lifestyle modifications to be followed to manage this condition?
Answer:

  1. Food items which are preferable: Whole grains, fruits and vegetables, low – fat dairy products, Green tea, Hibiscus tea, Pineapple juice and low carbohydrate food items.
  2. Food items to be avoided: Salt, Meat, Pickles, Canned Soups, Tomato products, sugar, packaged foods, White bread and packaged snacks, etc.

Other Life Style Modification:

  • Exercise for about 30 minutes.
  • Eat a heart-healthy diet.
  • Do not smoke or use tobacco.
  • Get regular health screenings.
  • Get enough quality sleep.

Samacheer Kalvi 10th Science Health and Diseases Additional Questions Solved

I. Fill in the blanks.

Question 1.
Tobacco is obtained from the Tobacco plant _____ and ______.
Answer:
Nicotiana tobacco and Nicotiana rustica.

Question 2.
The increased urine output, leading to dehydration is termed as ______.
Answer:
Polyuria.

Question 3.
The inflammation of throat and bronchi due to smoke of Tobacco lead to the conditions of _____ and ______.
Answer:
Bronchitis and Pulmonary tuberculosis.

Question 4.
The study of cancer is called ______.
Answer:
Oncology.

Question 5.
The uncontrolled division of cells destroy the surrounding tissue forming a tumour or ______.
Answer:
Neoplasm.

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Question 6.
_____ and ______ hydrocarbons present in tobacco smoke is carcinogenic causing Lung cancer.
Answer:
Benzopyrene and Polycyclic.

II. Write ‘True’ or ‘False’ for the following statements. Correct the false statements:

Question 1.
The psychological dependent persons feel that drugs do not help them to reduce stress.
Answer:
False.
Correct Statement: The psychological dependent persons feel that drugs help them to reduce stress.

Question 2.
Individuals should seek help from psychologists and psychiatrists to get relief from alcohol abuse.
Answer:
True.

Question 3.
Tobacco chewing does not cause oral cancer.
Answer:
False.
Correct Statement: Tobacco chewing causes oral cancer.

Question 4.
In Type – 2 Non – Insulin Dependent Diabetes Mellitus, the target cells respond to insulin and allow the movement of glucose into cells.
Answer:
False.
Correct Statement: In Type – 2 Non – Insulin Dependent Diabetes Mellitus, the target cells do not respond to insulin and does not allow the movement of glucose into cells.

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Question 5.
Low Carbohydrate food in the form of starch, complex sugars, and fibre-rich diets are more appropriate for the Dietary management pf Diabetes.
Answer:
True.

III. Expand the following abbreviations:

Question 1.

  1. CVD
  2. HDL
  3. PUFA
  4. NACO
  5. NGO
  6. ELISA
  7. WHO
  8. NCPCR
  9. CPCR
  10. LOL
  11. UV rays.

Answer:

  1. Cardio-vascular Disease
  2. High-Density Lipoprotein
  3. Polyunsaturated Fatty Acids
  4. National AIDS Control Organization
  5. Non-Government Organization
  6. Enzyme-Linked ImmunoSorbent Assay
  7. World Health Organization
  8. National Commission for Protection of Child Rights
  9. Commission for Protection of Child Rights
  10. Low-Density Lipoprotein
  11. Ultra Violet rays.

IV. Match the following:

Question 1.

1. Psychotropic drugs (a) Nicotine
2. Chronic metabolic disorder (b) Emphysema
3. Addiction to Tobacco (c) Polyphagia
4. Excess hunger (d) Polydipsia
5. Inflammation of lung alveoli (e) Mood Altering drugs
6. Loss of water leads to thirst (f) Diabetes Mellitus

Answer:

  1. (e) Mood Altering drugs
  2. (f) Diabetes Mellitus
  3. (a) Nicotine
  4. (c) Polyphagia
  5. (b) Emphysema
  6. (d) Polydipsia.

V. Choose the correct answer.

Question 1.
When powdered tobacco is taken through the nose, it is called ______.
(a) smoking
(b) stimulant
(c) snuffing
(d) addiction.
Answer:
(c) snuffing

Question 2.
Causative factor of cancer is called:
(a) Oncogenes
(b) Radiogenes
(c) Oestrogenes
(d) Carcinogens
Answer:
(d) Carcinogens

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Question 3.
Insulin deficiency due to the destruction of β – cells occur in ______.
(a) IDDM
(b) BMI
(c) NIDDM
(d) CVD.
Answer:
(a) IDDM

Question 4.
Which is not cancer?
(a) Leukaemia
(b) Glaucoma
(c) Sarcoma
(d) Carcinogen
Answer:
(b) Glaucoma

Question 5.
The HIV Virus attack the body’s disease – fighting mechanism and the individual is prone to infectious diseases.
(a) Erythrocytes
(b) Thrombocytes
(c) Lymphocytes
(d) platelets.
Answer:
(c) Lymphocytes

VI. Write the correct dates for the following:

Question 1.

  1. December 1st
  2. 4th February
  3. 7th November
  4. May 31st
  5. June 26th.

Answer:

  1. World AIDS Day
  2. World Cancer day
  3. National Cancer awareness day
  4. No Tobacco Day or World Anti-Tobacco day
  5. International day against Drug abuse and Illicit Trafficking.

VII. Answer the following briefly:

Question 1.
What are stimulants?
Answer:
Drugs that increase the activities of Central Nervous System.

Question 2.
What is abuse? What does it include?
Answer:
Abuse refers to cruel, violent, harmful or injurious treatment of another human being. It includes physical, emotional or psychological, verbal, child and sexual abuses.

Question 3.
List the instruction to be given to prevent child sexual abuse.
Answer:

  1. Do not talk to any suspected person or strangers and to maintain a distance.
  2. Not to be alone with unknown person.
  3. To be careful while travelling alone in public or private transport:
  4. Not to receive money, toys, gifts or chocolates from known or unknown person to them without the knowledge of their parents.
  5. Not to allow known or unknown person to touch them.

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Question 4.
What is an addiction? What is the effect of addiction on individuals?
Answer:
The physical and mental dependency on – alcohol, smoking and drugs are called addiction. The addictive potential of these substances pulls an individual into a vicious cycle leading to regular abuse and dependency.

Question 5.
What are the symptoms of diabetes?
Answer:
Diabetes mellitus is associated with several metabolic alterations. The most important symptoms are

  1. Increased blood glucose level (Hyperglycemia).
  2. Increased urine output (Polyuria) leading to dehydration.
  3. Loss of water leads to thirst (Polydipsia) resulting in increased fluid intake.
  4. Excessive glucose excreted in urine (Glycosuria).
  5. Excess hunger (Polyphagia) due to loss of glucose in urine.
  6. Fatigue and loss of weight.

Question 6.
Explain the types of cancers on the basis of the tissues from which they are formed?
Answer:
Cancers are classified on the basis of the tissues, from which they are formed:

  • Carcinomas arise from epithelial and glandular tissues.
  • Sarcomas occur in connective and muscular tissue. They include the cancer of bones, cartilage, tendons, adipose tissue and muscles.
  • Leukaemia is characterised by an increase in the formation of white blood cells in the bone marrow and lymph nodes Leukaemia is called blood cancers.

Question 7.
Name the test done to diagnosis Aids.
Answer:
The presence of HIV virus can be confirmed by western Blot analysis or Enzyme Linked Immunosorbent Assay (ELISA)

Question 8.
What is the treatment of cancer and the preventive measures for cancer?
Answer:
The treatment of cancer involves the following methods:

  • Surgery: Tumours are removed by surgery to prevent further spread of cancer cells.
  • Radiation therapy: Tumour cells are irradiated by lethal doses of radiation while protecting the surrounding normal cells.
  • Chemotherapy: It involves the administration of anticancerous drugs, which prevent cell division and are used to kill cancer cells.
  • Immunotherapy: Biological response modifiers like interferons are used to activate the immune system and help in destroying the tumours.

Preventive measures for cancer:

  • Cancer control programmes should focus on primary prevention and early detection.
  • To prevent lung cancer, tobacco smoking is to be avoided.
  • Protective measures to be taken against exposure to toxic pollutants of industries.
  • Excessive exposure to radiation is to be avoided to prevent skin cancer.

Question 9.
Explain the symptoms and treatment of AIDS.
Answer:

  • Infected individuals become immunodeficient.
  • The person becomes more susceptible to viral, bacterial, protozoan and fungal diseases.
  • Swelling of lymph nodes, damage to the brain, loss of memory, lack of appetite and weight loss, fever, chronic diarrhoea, cough, lethargy, pharyngitis, nausea and headache.

1. Diagnosis: The presence of the HIV virus can be detected by Western Blot Analysis or Enzyme – Linked ImmunoSorbent Assay (ELISA).
2. Treatment: Anti – retroviral drugs and immunostimulating therapy can prolong the life of the infected person.

Question 10.
Briefly note down the prevention and control of AIDS.
Answer:
The following steps help in controlling and preventing the spreading of HIV:

  • Screening of blood from blood banks for HIV, before transfusion.
  • Ensuring the use of disposable needles and syringes in hospitals and clinics.
  • Advocating safe sex and the advantages of using condoms.
  • Creating an awareness campaign and educating people on the consequences of AIDS.
  • Persons with HIV / AIDS should not be isolated from the family and society.

Question 11.
What is obesity and body mass Index?
Answer:
Obesity is the state in which there is an accumulation of excess body fat with an abnormal increase in body weight.
Body Mass Index (BMI) is an estimate of body fat and health risk.
BMI = Weight (kg) / Height (m)2

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Question 12.
What are the major causes and contributing factors for heart disease?
Answer:
Hypercholesterolemia (High blood cholesterol) and high blood pressure (Hypertension) are the major causes and contributing factors for heart disease.

  1. Heredity (family history)
  2. Diet rich in saturated fat and cholesterol
  3. Obesity, increasing age
  4. Cigarette smoking
  5. Emotional stress
  6. Sedentary lifestyle
  7. Excessive alcohol consumption and
  8. Physical inactivity are some of the causes.

VIII. Identify the first words and their relationship and suggest a suitable word for the fourth blank:

Question 1.
Drug abuse : addictive drug :: Tobacco chewing : ______.
Answer:
Oral cancer or mouth cancer.

Question 2.
Insulin : Diabetes :: Benzopyrene : ______.
Answer:
Lung cancer.

Question 3.
Disease of heart and blood vessels : Cardiovascular disease :: Deposition of cholesterol in the blood vessel : ______.
Answer:
Coronary Heart Disease (CHD).

Question 4.
Deficient blood supply to heart muscle : Ischemia :: Death of the heart muscle tissue : ______.
Answer:
Myocardial Infarction.

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Question 5.
HIV Virus : ELISA :: Leukaemia : ______.
Answer:
Blood cancer.

X. Explain the following in detail.

Question 1.
Explain the approaches for protection of an abused child and the prevention of child sexual abuse.
Answer:

  • Child helpline: The Child Helpline provides a social worker who can assist the child by providing food, shelter and protection.
  • Counselling the child: Psychologists and social workers should provide guidance, counselling and continous support to a victim child.
  • Family support: The victimized child should be supported by the family members. They should provide proper care and attention to child to overcome his/her sufferings.
  • Medical care: A child victim of sexual offences should receive medical care and treatment from health care professionals to overcome mental stress and depression.
  • Legal Counsel: The family or the guardian of the child victim shall be entitled to free assistance of a legal counsel for such offence.
  • Rehabilitation: Enrolling in schools and resuming their education is an important step towards the rehabilitation of the child.
  • Community – based efforts: Conducting awareness campaign on child abuse and its prevention.

Question 2.
List out the harmful effects of Alcohol to health.
Answer:
Prolonged use of alcohol depresses the nervous system, by acting as a sedative and analgesic substance. Some of the harmful effects are:

  1. Nerve cell damage resulting in various mental and physical disturbances.
  2. Lack of co-ordination of body organs.
  3. Blurred or reduced vision, results in road accidents.
  4. Dilation of blood vessels which may affect functioning of the heart.
  5. Liver damage resulting in fatty liver which leads to cirrhosis and formation of fibrous tissues.
  6. Body loses its control and consciousness eventually leading to health complications and ultimately to death.

Question 3.
Explain in detail the Smoking Hazards and effects of Tobacco. How can it be prevented?
Answer:
When smoke is inhaled, the chemicals get absorbed by the tissues and cause the following harmful effects:

  • Benzopyrene and polycyclic hydrocarbons present in Tobacco smoke are carcinogenic causing lung cancer.
  • Causes inflammation of throat and bronchi leading to conditions like bronchitis and pulmonary tuberculosis.
  • Inflammation of lung alveoli, decrease surface area for gas exchange and cause emphysema.
  • Carbon monoxide of Tobacco smoke binds to the haemoglobin of RBC and decreases its oxygen-carrying capacity causing hypoxia in body tissues.
  • Increased blood pressure caused by smoking leads to increased risk of heart disease.
  • Causes increased gastric secretion which leads to gastric and duodenal ulcers.
  • Tobacco chewing causes oral cancer (mouth cancer).

Prevention: Adolescents and old people need to avoid these habits. Proper counselling and medical assistance can help an addict to give up the habit of smoking.

XI. Higher Order Thinking Skills (HOTS) Questions

Question 1.
What do the following symbols represent?
Samacheer Kalvi 10th Science Solutions Chapter 21 Health and Diseases 1
Answer:
(a) 1. No Smoking
2. No Alcohol
3. No Psychotropic drugs
(b) 4. No – International Tobacco day
5. Inflammation of Lung Alveoli and decreased surface area.

Question 2.
Some human diseases are transmitted only through blood in one of such diseases, there is a progressive decrease in the number of lymphocytes of the patient.
(a) Name the disease and its causative agent.
(b) Write any two symptoms of it.
Answer:
(a) Name the disease is the AIDS caused by Human Immuno Deficiency Virus.
(b) Weight loss and lack of appetite are the symptoms of AIDS.

Question 3.
Which is the desirable blood cholesterol level for Indians?
Answer:
200 mg / dl.

Question 4.
Which cholesterol lowers the risk of heart disease and which cholesterol increases the risk of heart diseases?
Answer:

  • HDL (High – Density Lipoprotein) or good cholesterol lowers the risk of heart disease.
  • LDL (Low – Density Lipoprotein) or bad cholesterol increases the risk of heart diseases.

Question 5.
What are the two types of tumours?
Answer:

  • Benign tumours or Non – malignant tumours: Remain confined in the organ affected and do not spread to other parts of the body.
  • Malignant tumours: Mass of proliferating cells, which grow very rapidly invading and damaging the surrounding normal tissues.

Question 6.
Name some foods which help to reduce blood sugar levels.
Answer:
Flax seeds containing insoluble fibre, Guava, Tomatoes and spinach are the foods, which helps to reduce blood sugar levels.

Samacheer Kalvi 10th Science Solutions Chapter 21 Health and Diseases Read More »

Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life

You can Download Samacheer Kalvi 10th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life

Samacheer Kalvi 10th Science Origin and Evolution of Life Textual Evaluation Solved

I. Choose the Correct Answer.

Question 1.
Biogenetic law states that _____.
(a) Ontogeny and phylogeny go together.
(b) Ontogeny recapitulates phylogeny.
(c) Phylogeny recapitulates ontogeny.
(d) There is no relationship between phylogeny and ontogeny.
Answer:
(b) Ontogeny recapitulates phylogeny.

Question 2.
The ‘use and disuse theory’ was proposed by _____.
(a) Charles Darwin
(b) Ernst Haeckel
(c) Jean Baptiste Lamarck
(d) Gregor Mendel.
Answer:
(c) Jean Baptiste Lamarck

Question 3.
Paleontologists deal with _____.
(a) Embryological evidences
(b) Fossil evidences
(c) Vestigial organ evidences
(d) All the above.
Answer:
(b) Fossil evidences

Question 4.
The best way of direct dating fossils of recent origin is by _____.
(a) Radio – carbon method
(b) Uranium lead method
(c) Potassium – argon method
(d) Both (a) and (c).
Answer:
(a) Radio – carbon method

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Question 5.
The term Ethnobotany was coined by _____.
(a) Khorana
(b) J.W. Harshberger
(c) Ronald Ross
(d) Hugo de Vries.
Answer:
(b) J.W. Harshberger

II. Fill in the blanks.

Question 1.
The characters developed by the animals during their life time, in response to the environmental changes are called _____.
Answer:
Acquired characters.

Question 2.
The degenerated and non-functional organs found in an organism are called _____.
Answer:
Vestigial organ.

Question 3.
The forelimbs of bat and human are examples of ______ organs.
Answer:
Homologous.

Question 4.
The theory of natural selection for evolution was proposed by _____.
Answer:
Charles Darwin.

III. State whether True or False. If false, write the correct statement.

Question 1.
‘The use and disuse theory of organs’ was postulated by Charles Darwin?
Answer:
False.
Correct statement: ‘The use and disuse theory of organs’ was postulated by Jean Baptiste Lamarck.

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Question 2.
The homologous organs look similar and perform similar functions but they have different origin and developmental pattern?
Answer:
False.
Correct statement: The homologous organs look dissimilar and perform dissimilar functions, but they have the same origin and developmental pattern.

Question 3.
Birds have evolved from reptiles.
Answer:
True.

IV. Match the following:

Question 1.

Column A Column B
1. Atavism (a) caudal vertebrae and vermiform appendix
2. Vestigial organs (b) a forelimb of a cat and a bat’s wing
3. Analogous organs (c) rudimentary tail and thick hair on the body
4. Homologous organs (d) a wing of a bat and a wing of an insect
5. Wood park (e) radiocarbon dating
6. W.F. Libby (f) Thiruvakkarai

Answer:

  1. (c) rudimentary tail and thick hair on the body
  2. (a) caudal vertebrae and vermiform appendix
  3. (d) a wing of a bat and a wing of an insect
  4. (b) a forelimb of a cat and a bat’s wing
  5. (f) Thiruvakkarai
  6. (e) radiocarbon dating.

V. Answer in a word or Sentence

Question 1.
A human hand, a front leg of a cat, a front flipper of a whale and a bat’s wing look dissimilar and adapted for different functions. What is the name given to these organs?
Answer:
Homologous organs.

Question 2.
Which organism is considered to be the fossil bird?
Answer:
Fossil bird Archaeopteryx.

Question 3.
What is the study of fossils called?
Answer:
Palaeontology.

VI. Short Answers Questions

Question 1.
The degenerated wing of a kiwi is an acquired character. Why is it an acquired character?
Answer:
Kiwi does not have the need to fly that is why they do not have wings. The characters developed by the animals during their life in response to environmental changes. The vestigial wings are so small (invisible) under the bristly, hair-like two-branched feathers. So the degenerated wing of a kiwi is an acquired character.

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Question 2.
What is the study of fossils called?
Answer:
Palaeontology is called as the study of fossils.

Question 3.
Define Ethnobotany and write its importance.
Answer:
Ethnobotany is the study of a region’s plants and their practical uses through the traditional knowledge of the local culture of people.
Importance of Ethnobotany:

  • It provides traditional uses of the plant.
  • It gives information about certain unknown and known useful plants.
  • The ethnomedicinal data will serve as a useful source of information for the chemists, pharmacologists and practitioners of herbal medicine.
  • Tribal communities utilize ethnomedicinal plant parts like bark, stem, roots, leaves, flowers, flower bud, fruits, seeds, oils, resins, dyes and gum for the treatment of diseases like diarrhoea, fever, headache, diabetes, jaundice, snakebites and leprosy, etc.

Question 4.
How can you determine the age of the fossils?
Answer:
The age of fossils is determined by radioactive elements present in it. They may be carbon, uranium, lead or potassium.

VII. Long Answer Questions

Question 1.
Natural selection is a driving force for evolution-How?
Answer:
Darwin published his observations under the name “origin of species”. It elaborates on the theory of natural selection for evolutionary transformation.
The principles of Darwinism tells that natural selection is a driving force for evolution.

1. Overproduction: Living beings have the ability to reproduce and have the capacity to multiply in a geometrical manner.

2. Struggle for existence: Due to overproduction, a geometric ratio of increase in population occurs. The space to live and food available for the organisms remain the same. This creates a competition among the organisms, for food and space, leading to struggle.

  • The competition may be among the individuals of the same species (Intraspecific struggle).
  • Competition between the organisms of different species living together (Interspecific struggle).
  • Natural conditions like extreme heat or cold drought and floods can affect the existence of organisms (Environmental struggle).

3. Variations: Small variations are important for evolution. According to Darwin, favourable variations are useful to the organisms and unfavourable variations are harmful or useless to the organisms.

4. Survival of the fittest or Natural selection: During the struggle for existence, the organisms which can overcome the challenging situation, survive and adapt to the surrounding environment. Organisms, which are unable to face the challenges, are unfit to survive and disappear. The process of selection of organisms with favourable variation is called Natural selection.

5. Origin of species: According to Darwin, new species originates by the gradual accumulation of favourable variations for a number of generations.

Question 2.
How do you differentiate homologous organs from analogous organs?
Answer:

Homologous organs Analogous organs
1. The homologous organs have been inherited from common ancestors, with similar developmental pattern in embryos. 1. Analogous structures are shown in a batwing, a bird wing and an insect wing.
2. The forelimbs of a human hand, a front leg of a cat, the flipper of a whale and a bat’s, wing look dissimilar and adapted for different functions. 2. The analogous organs look similar but perform similar functions.
3. Their mode of development and the basic structure of bone are similar. 3. They have a different origin. Wings of insect are membranous extensions whereas wings of a bat is a bony structure. But performing the same function of flying.

Question 3.
How does fossilization occur in plants?
Answer:
A plant fossil is any preserved part of a plant that has died long back. Fossils may be a prehistoric impression that may be hundred to millions of years old. Majority of the plant fossils are disarticulated parts of plants, it is rare to find plants to be preserved as whole.

VIII. Higher Order Thinking Skills (HOTS) Questions

Question 1.
Arun was playing in the garden. Suddenly he saw a dragonfly sitting on a plant. He observed the wings of it. He thought it looked similar to a wing of a crow. Is he correct? Give a reason for your answer.
Answer:
No. He is not correct. Both crow and dragonfly have the same function of flying with wings. But it’s the origin (basic structure) is different. Dragonfly wing is the membranous extension. But the wing of the crow is the modification of forelimb.

Question 2.
Imprints of fossils tell us about evolution- How?
Answer:
Fossil records show that evolution has taken a gradual process from simple to complex organisms. The study of fossils helps us to understand the link of evolution. The origin of modem birds is supported by the evidence of palaeontology.

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Question 3.
Octopus, cockroach and frog all have eyes. Can we group these animals together to establish a common evolutionary origin? Justify your answer.
Answer:
Convergent evolution is the process, by which the independently evolved features, may similar to each other, but can arise through different developmental pathways. So the octopus, cockroach and frog all have eyes. The independently evolved eye may similar in each other, but can arise through different developmental pathways.

Samacheer Kalvi 10th Science Origin and Evolution of Life Additional Questions Solved

I. Fill in the blanks.

Question 1.
The history of life has two aspects namely ______ and ______.
Answer:
Origin of life; The evolution of life.

Question 2.
The theory which postulates that life originates from pre – existing life is ______.
Answer:
Biogenesis.

Question 3.
_____ is the gradual change occurring in living organisms over a period of time.
Answer:
Evolution.

Question 4.
Sexual reproduction, which involves meiosis helps in the recombination of ______ during gametic fusion.
Answer:
Genes.

Question 5.
The major concept in astrobiology is the ______.
Answer:
Habitable zone.

Question 6.
The organisms, which live in extreme environmental conditions on Earth are called ______.
Answer:
Extremophiles.

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Question 7.
Fossil records show that evolution has taken a gradual process from simple to _______ organisms.
Answer:
Complex.

II. Match the following:

Question 1.

1. Big Bang theory (a) study of regions and practical use of plants
2. Petrifaction (b) organisms buried and cause depression
3. Archaeopteryx (c) other names for astrobiology
4. Ethnobotany (d) preserve hard and soft parts
5. Mould (e) origin of the universe
6. Exobiology (f) fossil bird

Answer:

  1. (e) origin of the universe
  2. (d) preserve hard and soft parts
  3. (f) fossil bird
  4. (a) study of regions and practical use of plants
  5. (b) organisms buried and cause depression
  6. (c) other names for astrobiology.

Question 2.

1. Oparin and Haldane (a) use and disuse theory
2. Ernest Haeckel (b) Mutation theory
3. Leonardo da Vinci (c) Father of Indian palaeobotany
4. Jean Baptiste Lamarck (d) Life from the chemical reaction
5. Darwin (e) Father of palaeontology
6. De Vries (f) Radioactive carbon
7. Birbal Sahni (g) Ethnobotany
8. W.F. Libby (h) Origin of species
9. J.W. Harshberger (i) Biogenetic law

Answer:

  1. (d) Life from a chemical reaction
  2. (i) Biogenetic law
  3. (e) Father of palaeontology
  4. (a) use and disuse theory
  5. (h) Origin of species
  6. (b) Mutation theory
  7. (c) Father of Indian palaeobotany
  8. (f ) Radioactive carbon
  9. (g) Ethnobotany.

III. Choose the correct answer.

Question 1.
The theory of idea embodies that life on Earth is a divine creation ______.
(a) chemical reaction
(b) special creation
(c) spontaneous generation
(d) Biogenesis.
Answer:
(b) special creation

Question 2.
Palaeontology deals with the study of ______.
(a) analogous organs
(b) fossils
(c) gradual change
(d) homologous organ.
Answer:
(c) gradual change

Question 3.
The other name for continuous variation is ______.
(a) germinal variation
(b) somatic variation
(c) discontinuous variation
(d) fluctuating variation.
Answer:
(d) fluctuating variation.

Question 4.
It is a branch of palaeontology that deals with the recovery and identification of plant remain of geological past ______.
(a) palaeobotany
(b) Embryology
(c) mutation
(d) palaeontology.
Answer:
(a) palaeobotany

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Question 5.
Book ‘Philosophic Zoologique’ published in the year 1809 was written by:
(a) Darwin
(b) Lamarck
(c) Wallace
(d) Mendel
Answer:
(b) Lamarck

IV. Answer the following shortly.

Question 1.
What is Abiogenesis?
Answer:
Abiogenesis or spontaneous generation theory states that life originated spontaneously from lifeless matter. It was believed that fishes originated from mud, frogs from moist soil and insects from decaying matter.

Question 2.
What is the cosmic origin?
Answer:
Cosmic origin of extraterrestrial theories states that life came from outer space. The unit of life called spores (panspermia) were transferred to different planets including Earth.

Question 3.
What is the chemical evolution of life?
Answer:
Chemical evolution of life theory states that life arose by a series of sequential chemical reactions. The first form of life could have come from pre – existing non – living inorganic molecules, which gave rise to the formation of diverse organic molecules, which are transformed into a colloid system to produce life.

Question 4.
Name the evidence of evolution What do they support?
Answer:

  • Evidence from morphology and Anatomy.
  • Evidence from embryology.
  • Evidence from palaeontology.

Evolution is best understood by observing the relationship between the existing organisms and the similarities of the extinct organisms. This evidence supports the concept that all organisms have evolved from common ancestors.

Question 5.
Explain the evidence of evolution from Embryology.
Answer:
The embryos from fish to mammals are similar in their early stages of development. The study of comparative embryology of different animals supports the concept of evolution. The differentiation of their special characters appears in the later stages of development. Ontogeny recapitulates phylogeny. The stages of development of the individual animal repeat the evolutionary history of the entire race of the animal.
Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life 1

Question 6.
Represent a flow chart showing the postulates of Lamarckism?
Answer:
The postulates of Lamarckism:
Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life 2

Question 7.
Explain the evidence of evolution from palaeontology.
Answer:
Palaeontology deals with the study of fossils. The study of fossils helps us to understand the line of evolution of many invertebrates and vertebrates. Fossil records show that evolution has taken a gradual process from simple to complex organisms.

The origin of modem birds is supported by the evidence from palaeontology. Archaeopteryx is the oldest known fossil bird. It is considered to be a connecting link between reptiles and birds. It had wings with feathers, like a bird. It had a long tail, clawed digits and conical teeth like a reptile.

Question 8.
What is evolution?
Answer:
Formation of new species due to changes in specific characters over several generations as a response to natural selection is called evolution. Evolution is the gradual change occurring in living organisms over a period of time.

Question 9.
Represent a flow chart showing the postulates of Darwinism?
Answer:
The postulates of Darwinism:
Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life 3

Question 10.
Explain the types of variation?
Answer:
Variations are the differences found among individuals of the same species and the offspring of the same parent. New species originate by the gradual accumulation of variations. Evolution would not be possible without variation.
Somatic variation and germinal variation are the two types of variations:

  1. Somatic variation: The variation which affects the body (somatic) cells of the organisms are called somatic variation, which is not heritable. They occur due to environmental factors.
  2. Geminal variation: The variations, which are produced in germ cells and inherited are called germinal variation. They are classified into two types.
    • Continuous variation: Small variations which occur among individuals of a population, and occur by gradual accumulation is called continuous variation. They are also called fluctuating variation, e.g. skin colour, height and weight and colour of the eye, etc.
    • Discontinuous variation: These changes are sudden, which occur in an organism, due to mutations. These large variations are not useful for evolution, e.g. short – legged Ancon sheep and six or more digits (fingers) in human, etc.

Question 11.
Explain the importance of fossils?
Answer:
Importance of fossils:

  1. They throw light on phylogeny and evolution of plants.
  2. Fossil plants give a historical approach to the plant kingdom.
  3. Fossils are useful in the classification of plants.
  4. Fossil plants can be used in the field of descriptive and comparative anatomy.

Question 12.
What are Extremophiles?
Answer:
The organisms which live in extreme environmental conditions on Earth are called extremophiles within our own solar system, there are many areas that are different from the Earth. We may find the presence of life similar to extremophile bacteria.

Question 13.
What is Astrobiology or Exobiology? What does it deal?
Answer:
Astrobiology or exobiology is the science which looks for the presence of extraterrestrial in the universe.
Astrobiology deals with the origin, evolution and distribution of life in the universe and to investigate the possibility of living in another world.

The major concept in astrobiology is the habitable zone. Astrobiology explains that any planets can support the existence of life if it fulfils two criteria:

  • It must have the right mass to retain an atmosphere.
  • It must have an orbit at the right distance from Sun, that it allows liquid water to exist. The distance needs to be neither too hot nor too cold and is often called the Goldilocks zone for life.

V. Answer the following in detail.

Question 1.
Explain in detail with diagrams, the evidence of evolution, through morphology and anatomy.
Answer:
The comparative study of morphology and anatomy of organisms have evolved from a common ancestor.
Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life 4
(i) Homologous organs: The homologous organs are those which have inherited from common ancestors with similar developmental pattern in embryos. The forelimbs of mammals are homologous structures. A human hand, a front leg of a cat, flipper of a whale and a bat’s wing look dissimilar and adapted for different functions. Their mode of development and the basic structure of bone are similar.

(ii) Analogous organs: The analogous organs look similar and perform similar functions but they have different origin and developmental pattern. The function of the wings of a bat, the wings of a bird and wings of an insect are similar, but their basic structures are different.

(iii) Vestigial organs: The degenerated and non¬functional organs of animals are called vestigial organs. The same organs are found to be well- developed and functional, in some of the related forms. Some of the vestigial organs in man are a vermiform appendix, nictitating membrane, caudal vertebra and coccyx, etc.

(iv) Atavism: The reappearance of ancestral characters in some individuals is called atavism, e.g. Presence of rudimentary tail in newborn babies, the presence of thick hair on the human body.
Samacheer Kalvi 10th Science Solutions Chapter 19 Origin and Evolution of Life 5

Question 2.
(a) Name the popular names of Lamarckism.
(b) Explain the principles of Lamarckism.
Answer:
(a) Lamarckism is the hypothesis that an organism can pass on characteristics, that it has acquired through use or disuse, during it’s lifetime to the offspring. Lamarck’s theory of evolution was published in ‘Philosophic Zoologique’ in the year 1809. Lamarckism is popularly known as ‘Theory of inheritance of Acquired Characters” or “Use and Disuse theory”

(b) (i) internal vital force: Due to the inherent ability of the living organisms or their component parts tend to increase in ‘ size continuously.

(ii) Environment and new needs: A change in the environment brings about changes in the need of the organisms. In response to the changing environment, the organisms develop certain adaptive characters. The adaptations may be in the form of development of new parts of the body.

(iii) Use and disuse theory: Lamarck’s use and disuse theory state that, if an organ is used constantly, the organ develops well and gets strengthened. When an organ is not used for a long time, it gradually degenerates. The ancestors of Giraffe were provided with a short neck and short forelimbs. Due to a shortage of grass, they are forced to feed on leaves from trees. The continuous stretching of their neck and forelimbs resulted in the development of long neck and long forelimbs, which is an example fcc constant use of an organ. The degenerated wing of Kiwi is an example for organ of disuse.

(iv) Theory of Inheritance of acquired characters: Animals respond to the changes when there is a change in the environment. The develop adaptive structures. The characters, developed during their lifetime, in response to the environmental changes are called acquired characters. The acquired characters are transmitted to the offspring by the process of inheritance.

VI. Higher-Order Thinking skills [HOTS] Questions

Question 1.

  1. What is the reason for the long neck of a giraffe.
  2. Name the theory based on the shown figure.

Answer:

  1. Due to a shortage of grass, they were forced to feed on leaves from trees. The continuous stretching of their neck and forelimb as resulted in the development of a long neck and long forelimbs.
  2. Theory of inheritance of acquired characters.

Question 2.
What are living fossils?
Answer:
Living fossils are living organisms that are similar in appearance to their fossilized distant ancestors and usually have no extinct close features, eg. Ginko Biloba.

Question 3.
What is Mars 2020 Astrobiology?
Answer:
NASA is developing the Mars 2020, Astrobiology to investigate an astrobiological relevant ancient environment on Mars, its surface geological processes and the possibility of past life on Mars and preservation of biosignatures within accessible geological materials.

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Samacheer Kalvi 10th English Expansion of Outlines / Hints

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Expansion of Outlines / Hints

Write a paragraph using the following outlines in about 100 words.
1. Action against legal permissions to spoil environment – movement – codification of ecocide as a fifth crime against peace – to transform our understanding of nature – sustainable use of Nature – formidable challenges – Awareness up – Paris Climate agreement – prevent crimes against Nature.

Codification Of Ecocide

The current legal regime allows states and corporations to despoil the environment with impunity. This injustice has inspired a new movement of legal experts and citizens calling for the codification of ecocide as a fifth crime against peace, joining genocide, crimes of aggression, crimes against humanity, and war crimes. Their work aims to transform our understanding of nature from property to an equal partner with humans in building sustainable societies. The political and enforcement hurdles are formidable, but an awakened and engaged citizenry, strengthened by the Paris Climate agreement, may prove powerful enough to elevate the prevention of crimes against nature to an internationally recognized norm.

“Join hands and prevent Crimes against Nature.”

Samacheer Kalvi 10th English Expansion of Outlines / Hints

2. The problem of Global Warming – to be controlled – minimizing the emission of greenhouse gases into the environment – preventive steps – Laws. Reduction in thermal power generating stations. – We should not waste paper, planting trees and carpooling – save the earth from the harmful effects.

Global Warming

We need to control the effects of global warming. Emission of greenhouse gases can be minimized by some methods. The Laws that govern pollution and greenhouse gases should be followed. Reduced dependence on thermal power for our electricity need would help towards reducing the quantity of carbon dioxide in the environment. The use of fossil fuels for generating conventional energy is a major contributor of greenhouse gases. We can save paper by keeping documents in electronic format and by not printing emails.. Trees absorb carbon dioxide and releases oxygen. Trees are helpful in reducing the problem of global warming. We can share our cars while going to office or performing other scheduled activities. On one hand, we will save money, and on the other, we will emit less greenhouse gases.

“Consider Car pooling as one of the options.”

3. A farmer – sons lazy – death bed – anxious – calls sons – dies disclosing secret – gold buried in their dry neglected farm land – Dies – sons dig up – whole farm turned upside – deeply dug – two places water found – gold not found – decide to build two wells – do agriculture – rich in the next decade – wonder – where is gold – ripe paddy shine in sunlight – realize truth

Wise Old Father

Once a farmer became old. He was worried as his sons were very lazy. The farm land was left fallow for four years . Thoms and weeds had grown all over. One evening, he realized that his end was very near. The thought of his sons did not permit him to die in peace. An idea flashed across his mind. He called his sons and said that he had saved every thing in gold and buried them in the farm. The sons sat around the dying man three days on turn to get the information as to where he had buried the gold. But the old man went into a coma and died on the fourth day. The sons were angry but decided to find the hidden treasure. They did not hire others because they wanted the gold for themselves. They dug the whole land .They had dug it very deep in two places from where water started gurgling and pouring out. They built two wells and started farming with the hope they would find the gold one day. After ten years they had become rich and become respected folks in the village. One day the elder son saw the ripe com shining in the golden sunlight. He exclaimed, “ I found the gold”. His brothers asked, ’’where?”. Look at the glistening paddy grains. Our old man has conned us into farm work. Anyway it was for our good only. Had he not made us greedy, we would have wasted our youth in idleness. Let us go and white wash the grave of the old man we had neglected so long. The brothers smiled and agreed.

“Reap what you sow.”

4. India – Solar energy – over 300 million houses – over 300 days of sunshine – target of 40 GW of rooftop solar by 2020 – solar panels – on the roofs of commercial, government and institutional buildings – no break through in the residential sector – a few cities adopt rooftop solar energy – December 2015, the Indian government offer – INR 50 billion (USD 750 million) – for 30% capital subsidy for rooftop solar installations – target of
4.2 GW by 2020 – yet growth restricted to commercial organizations.

Roof Top Solar Energy

With over 300 million houses in India, over 300 days of sunshine, an ambitious target of 40 GW of rooftop solar by 2020 and various states formulating rooftop solar policies, there should have been a solar revolution in Indian homes. Yet, the situation on the ground is quite different. In the building sector, solar panels are primarily finding their way on the roofs of commercial, government and institutional buildings. Unfortunately, there has not been any major breakthrough in the residential sector. There are only a handful that has opted for rooftop solar energy in the cities despite high environmental awareness and access to technology and support.In December 2015, the Indian government rolled out INR 50 – billion (USD 750 million) funding for 30% capital subsidy for rooftop solar installations to create a total capacity of 4.2 GW by 2020. But that has not made the power of natural light attractive enough for consumers or even for solar developers, who are largely focusing on the commercial buildings and institutions.

“Work towards a Developed India.”

5. Earth Day – celebrated on April 22 every year – pledge to protect earth’s environment – soil, water, air polluted by modern factories – large amounts of waste generated everyday – wet and dry waste material to be separated – dry waste used for recycling – wet waste such as vegetable peel, fallen leaves, cow dung, etc. used as manure – for cultivation – pollution-free earth – our aim.

Earth protection

Every year we celebrate Earth Day on 22nd April. Lovers of environment and students take a pledge to protect the earth’s environment. Modem factories pollute water, air and soil. Every day large amounts of waste is generated. We need to do waste management wisely. We have to segregate wet and dry waste. Dry waste must be recycled. Wet waste such as vegetable peel, fallen leaves, cow dung etc must be composted and turned into manure. This natural manure is good for cultivation. By avoiding chemical fertilizers, we can make the earth free from pollution also. Keeping our dear earth free from pollution should be our motto.

“Save Mother Earth from Pollution.”

Samacheer Kalvi 10th English Expansion of Outlines / Hints

6. Temperature increase – year by year – season changes – monsoon – fails – rainfall – impair – glacier melts – sea level increases – cutting trees mindlessly – save forest – develop – social forest.

The Need for Social Forestry

Year by year, the temperature has been increasing steadily. There have been erratic seasonal changes in recent times. There is failure of monsoon hitting the agriculture sector hard in India. Due to the mindless felling of trees, there is a phenomenal increase in the climate which has started melting the glaciers. This threatens to raise the sea level and drown all the low lying countries of the world. It is high time we stopped felling of trees and saved the forests. Social forestry is the only way to involve the community in nurturing and protecting forests. If we don’t conserve forests we will perish as a race.

“Plant Trees! Grow Trees!”

7. Sound mind in a sound body – giving importance only to study – sports necessary – shape personality – study and no play – make dull – train – leadership – co-operation – keep good health – discipline.

Sound Mind in a Sound Body

Unfortunately, in many families importance is given only to studies. In some cases, even the health of the child is neglected. It is wise to give equal importance to sports. Physical exercises through regular participation in sports and games, shapes one’s personality. All study and no play make Tom a dull boy. Parents should realize that book worms succeed in examinations but fail in life. Sports only teaches leadership qualities, team spirit and nurtures co–operation among peers. Sports helps one develop discipline and also maintain good health. So, students must pay equal attention to studies and sports to succeed in life.

“Sports makes you focussed and reach your target.”

8. National integration – need of the hour – dividing forces – language, religion, etc. – _ develop tolerance – give up fights – encourage broadmindedness – patience – courteous behavior – patriotism – unity results in victory – peace – happiness.

Be United and Develop Tolerance

National integration is the need of the hour. There are various divisive forces operating on the basis of religion, language, caste and creed. They often carry out activities with the sole aim of disrupting peace and harmony. We need to integrate all these groups into a broader natural spectrum, however painstaking it may be. We have to make relentless efforts to inculcate in them a spirit of tolerance broad mindedness, patience and patriotism. They must be persuaded to give up their militant ways. Ultimately, an united nation will always stand firm in its resolve to assure peace and prosperity to its citizens and victory against its enemies.

“Be united to stay strong.”

9. Weekend holiday necessary – rest after a week of heavy work – can pursue our hobbies – do whatever we enjoy like (examples) – result: refreshed for the next week – no stress, Better performance – better attitude and behavior.

Be Refreshed to Work

Most of the people work hard to make a living. If they work 24 x 7, all over the week without rest, life would naturally become a drudgery. The best way out is to spend the weekend holidays with family members happily. One can spend time in pursuing one’s favorite hobbies like trekking, gardening, fishing, or just watching the beauty of waves meeting the silent shore with noise. One can visit friends or relatives and have one’s emotional batteries recharged. One can visit holy temples, churches or mosques and simply give rest to both the mind. Being quiet and doing nothing for a while helps one introspect to find if one could better the way one relates oneself to others. If all the above is not possible, one can see a good movie and forget the office or hard work. Once a person is refreshed this way, he/she would be stress – free and refreshed to take on the new week’s work with joy and cheerful attitude.

“Lead a meaningful life.”

Samacheer Kalvi 10th English Expansion of Outlines / Hints

10. Without hard work – no knowledge – all things – difficult initially – climbing mountains – get arduous training live in camps – minimum food – more hardships – risking life – lesson – no achievement without self – sacrifice – adequate – preparation – high achievers – overcome more difficulties.

Importance of Hardwork

No one can acquire knowledge without doing hard work. All strenuous work may appear very difficult initially. But practice would enable the person to accustom oneself to highly demanding things like mountain climbing also easy. In fact, trekking involves arduous training and the need to manage with minimum food in hostile weather and environment. One may have to risk life in doing such adventure sports. All great accomplishments do require long spells of hardships, training and a lot of self – sacrifice. One becomes a high achiever only after he/she overcomes a lot of difficulties through patience and persistence.

“Perseverance is the key to success.”

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Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management

You can Download Samacheer Kalvi 10th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management

Samacheer Kalvi 10th Science Environmental Management Textual Evaluation Solved

I. Fill in the blanks.

Question 1.
Deforestation leads to ______ in rainfall.
Answer:
Reduction

Question 2.
Removal of soil particles from the land is called ______
Answer:
Soil erosion

Question 3.
Chipko movement is initiated against ______
Answer:
the cutting down of trees

Question 4.
______ is a biosphere reserve in Tamilnadu.
Answer:
Nilgiris

Question 5.
Tidal energy is ______ type of energy.
Answer:
Non-conventional or renewable

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Question 6.
Coal, petroleum and natural gas are called ______ fuels.
Answer:
Fossil

Question 7.
______ is the most commonly used fuel for the production of electricity.
Answer:
Coal

II. State whether True or False. If false, write the correct statement:

Question 1.
Biogas is a fossil fuel.
Answer:
False
Correct statement: Biogas is the mixture of methane, hydrogen sulphide, carbon-di-oxide and hydrogen.

Question 2.
Planting trees increase the groundwater level.
Answer:
True

Question 3.
Habitat destruction caused loss of wildlife.
Answer:
True

Question 4.
Nuclear energy is renewable energy.
Answer:
False
Correct statement: Nuclear energy is a non-renewable energy source. The material used in nuclear plants is not renewable.

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Question 5.
Overgrazing prevents soil erosion.
Answer:
False
Correct statement: During overgrazing, most of the plants are eaten up. If the plants or vegetation is retained, the soil is not exposed. Soil erosion occurs due to overgrazing.

Question 6.
Poaching of wild animals is a legal act.
Answer:
False
Correct statement: Poaching should be prohibited.

Question 7.
The national park is a protected park.
Answer:
True

Question 8.
Wildlife protection act was established in 1972.
Answer:
True

III. Match the following:

Question 1.

Column A Column B
1. Soil erosion (a) energy saving
2. Bio-gas (b) acid rain
3. Natural gas (c) removal of vegetation
4. Greenhouse gas (d) renewable energy
5. CFL bulbs (e) CO2
6. Wind (f) non-renewable energy
7. Solid waste (g) lead and heavy metals

Answer:

  1. (c) Removal of vegetation
  2. (d) Renewable energy
  3. (f) Non-renewable energy
  4. (e) CO2
  5. (a) energy saving
  6. (b) acid rain
  7. (g) Lead and heavy metals

IV. Choose the correct answer:

Question 1.
Which of the following is/are a fossil fuel?
i. Tar
ii. Coal
iii. Petroleum
(a) i only
(b) i and ii
(c) ii and iii
(d) i, ii and iii
Answer:
(c) ii and iii

Question 2.
What are the steps will you adopt for better waste management?
(a) reduce the amount of waste formed
(b) reuse the waste
(c) recycle the waste
(d) all of the above
Answer:
(d) all of the above

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Question 3.
The gas released from vehicles exhaust is _________
i. Carbon monoxide
ii. Sulphur dioxide
iii. Oxides of nitrogen
(a) i and ii
(b) i and iii
(c) ii and iii
(d) i, ii and iii
Answer:
(d) i, ii and iii

Question 4.
Soil erosion can be prevented by:
(a) deforestation
(b) afforestation
(c) over growing
(d) removal of vegetation
Answer:
(b) afforestation

Question 5.
A renewable source of energy is ______
(a) petroleum
(b) coal
(c) nuclear fuel
(d) trees
Answer:
(d) trees

Question 6.
Soil erosion is more where there is:
(a) no rain fall
(b) low rainfall
(c) rain fall is high
(d) none of these
Answer:
(c) rain fall is high

Question 7.
An inexhaustible resources is _______
(a) wind power
(b) soil fertility
(c) wildlife
(d) all of the above
Answer:
(d) all of the above

Question 8.
Common energy source in village is:
(a) electricity
(b) coal
(c) biogas
(d) wood and animal dung
Answer:
(d) wood and animal dung

Question 9.
The greenhouse effect refers to _____
(a) cooling of Earth
(b) trapping of UV rays
(c) cultivation of plants
(d) warming of Earth
Answer:
(d) warming of Earth

Question 10.
A cheap, conventional, commercial and inexhaustible source of energy is:
(a) hydropower
(b) solar energy
(c) wind energy
(d) thermal energy
Answer:
(c) wind energy

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Question 11.
Global warming will cause _______
(a) raise in the level of oceans
(b) melting of glaciers
(c) sinking of islands
(d) all of these
Answer:
(d) all of these

Question 12.
Which of the following statement is wrong with respect to wind energy?
(a) wind energy is a renewable energy
(b) the blades of wind mill are operated with the help of electric motor
(c) production of wind energy is pollution free
(d) usage of wind energy can reduce the consumption of fossil fuels
Answer:
(b) the blades of wind mill are operated with the help of electric motor

V. Answer in a Sentence.

Question 1.
What will happen if trees are cut down?
Answer:
Soil erosion occurs and ecological imbalance takes place if trees are cut down.

Question 2.
What would happen if the habitat of wild animals is disturbed?
Answer:
If the habitat of wild animal is disturbed it leads to extinction of animals or on the verge of extinction.

Question 3.
What are the agents of soil erosion?
Answer:
The high velocity of wind, air currents, flowing water, landslide, human activities such as deforestation, farming and mining, and overgrazing by cattle are the agents of soil erosion.

Question 4.
Why fossil fuels are to be conserved?
Answer:
The formation of fossil fuels is a very slow process and takes very long period of time for renewals so fossil fuels are to conserved.

Question 5.
Solar energy is renewable energy. How?
Answer:
Solar energy is renewable, free source of energy, that is sustainable and totally inexhaustible.

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Question 6.
How are e- wastes generated?
Answer:
e-wastes are spoiled, out dated, non-repairable, electrical and electronic devices like computer components electronic and electrical appliances.

VI. Short Answer Questions

Question 1.
What is the importance of rainwater harvesting?
Answer:
The importance of rainwater harvesting is as follows:

  • overcome the rapid depletion of groundwater levels.
  • To meet the increased demand for water.
  • Reduces flood and soil erosion.
  • Water stored in-ground is not contaminated by human and animal wastes and hence can be used for drinking purpose.

Question 2.
What are the advantages of using biogas?
Answer:

  1. It bums without smoke and therefore causes less pollution.
  2. An excellent way to get rid of organic wastes like bio-waste and sewage material.
  3. Left over slurry is a good manure rich in nitrogen and phosphorus.
  4. It is safe and convenient to use.
  5. It can reduce the amount of greenhouse gases emitted.

Question 3.
What is the environmental effect caused by sewage?
Answer:

  • Sewage is the leading polluter of water resources in India.
  • Different species of fishes are killed.
  • Contaminated water can cause diseases such as e-coli, diarrhoea and hepatitis A.

Question 4.
What are the consequences of deforestation?
Answer:
Deforestation gives rise to ecological problems like floods, drought, soil erosion, loss of wild life, extinction of species, imbalance of biogeochemical cycles, alteration of climatic conditions and desertification.

VII. Long Answer Questions

Question 1.
How does rainwater harvesting structures recharge groundwater?
Answer:
Rainwater harvesting is a technique of collecting and storing rainwater for future use. The main purpose of rainwater harvesting is to make the rainwater percolate under the ground, so as to recharge ‘groundwater level’.

Methods of rainwater harvesting
(i) Rooftop rainwater harvesting: The rainwater that falls on the roof of the houses, apartments and commercial buildings, etc, is collected and stored in the surface tank and is used for domestic purpose.

(ii) Recharge pit: The collected rainwater is directed into the percolation pits through pipes for Alteration. After Alteration, the rainwater enters the recharge pits or ground wells.

  • Digging of tanks or lakes (Eris): Eris is constructed in such a way that, if the water in one eri overflows, it automatically gets diverted to the eri of the next village, as these eris are interconnected.
  • Ooranis: These are small ponds to collect rainwater. They are used for various domestic purposes.

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Question 2.
How will you prevent soil erosion?
Answer:

  1. Retain vegetation cover, so that soil is not exposed.
  2. Cattle grazing should be controlled.
  3. Crop rotation and soil management improve soil organic matter.
  4. Runoff water should be stored in the catchment.
  5. Reforestation, terracing and contour ploughing.
  6. Wind speed can be controlled by planting trees in form of a shelter belt.

Question 3.
What are the sources of solid wastes? How are solid wastes managed?
Answer:
Solid wastes mainly include municipal wastes, hospital wastes, industrial wastes and e-wastes, etc. The solid wastes are dumped in the soil, which results in landscape pollution. Solid-waste management involves the collection, treatment and proper disposing of solid material that is discarded from the household and industrial activities.

Methods of solid wastes disposal:

  • Segregation: It is the separation of different type of waste materials like biodegradable and non-biodegradable wastes.
  • Sanitary landfill: Solid wastes are dumped into low lying areas. The layers are compacted by trucks to allow settlement. The waste materials get stabilised in about 2-12 months. The organic matter undergoes decomposition.
  • Incineration: It is the burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature.
  • Composting: Biodegradable matter of solid wastes is digested by microbial action or earthworms and converted into humus.

Question 4.
Enumerate the importance of forest.
Answer:
Forests are an important component of our environment and are dominated by microorganisms, flowering plants, shrubs, climbers, dense trees and provide a vast habitat for wild animals. Forests also contribute to the economic development of our country. Forests are vital for human life, it is a source for a wide range of renewable natural resource. They provide wood, food, fodder, fibre and medicine.

Forests are major factor of environmental concern. They act as a carbon sink, regulate climatic conditions, increase rainfall, reduce global warming, prevent natural hazards like flood and landslides, protect wildlife and also act as catchments for water conservation. They also play a vital role in maintaining ecological balance.

Question 5.
What are the consequences of soil erosion?
Answer:
The consequences of soil erosion are as follows:

  • It has led to increased pollution and sedimentation in streams and rivers.
  • Clogging the waterways and causing a decrease in fish species.
  • Degraded lands often have less ability to hold on to water.
  • Topsoil is removed.
  • Topsoil quality is reduced.
  • No medium crops to grow in soil with poor quality.
  • Use of artificial fertilizers.
  • Disrupts ecosystem.

Question 6.
Why is the management of forest and wildlife resource considered as a challenging task?
Answer:
People would consider forest is a source of raw materials for the factories and industries, and utilise it for development of human without considering about other organism. There are many stake holders of forest. They are those people who are directly or indirectly involved in forest. Management of forest and called life has to take into account the interest of all stake holders which become a challenging task.

VIII. Assertion and Reasoning Questions

In each of the following question, a statement of assertion (A) is given and a corresponding statement of Reason (R). Of the four statements given below mark the correct answer.
(a) Both assertion and reason are true and the reason is the correct explanation of assertion.
(b) Both assertion and reason are true but the reason is not the correct explanation of assertion.
(c) Assertion is true but the reason is false.
(d) Both assertion and reason are false.

Question 1.
Assertion: Rainwater harvesting is to collect and store rainwater.
Reason: Rainwater can be directed to recharge the underground water source.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of assertion.

SamacheerKalvi.Guru

Question 2.
Assertion: Energy-efficient bulbs like CFL must be used to save electric energy.
Reason: CFL bulbs are costlier than ordinary bulbs, hence using ordinary bulbs can save our money.
Answer:
(c) Assertion is true but the reason is false.

IX. Higher Order Thinking Skills (HOTS) Questions

Question 1.
Although coal and petroleum are produced by the degradation of biomass, yet we need to conserve them. Why?
Answer:

  • The coal and petroleum reserves can get exhausted, if we use them at a rapid rate.
  • The formation of fossil fuel is a very slow process and takes a very long time for renewal.
  • It is necessary to conserve the resource, for the future generation, by reducing their consumption.

Question 2.
What are the objectives for replacing non-conventional energy resources from conventional energy resources?
Answer:
Non conventional energy resources are non-polluting renewable sources which are environmentally clean. It is available in unlimited amount in nature and they can be renewed over a short period of time inexpensive and can be harvested continuously.

Question 3.
Why is the Government imposing a ban on the use of polythene bags and plastics? Suggest alternatives. How is this ban likely to improve the environment?
Answer:
Government is imposing a ban on the use of plastic bags and plastics because,

  • Plastics pollute on land, rivers, ponds and all water bodies and soil, etc.
  • Burning of plastic in open air leads to environmental pollution, due to the release of poisonous gas.
  • The accumulation of plastic bags and plastics prevent the seeping of water into the Earth, which brings down the levels of groundwater.
  • Plastic bags can travel long distances by wind and water. They litter our landscapes and water bodies.

Alternatives:

  • Bring your own containers and bags to buy things from the shop.
  • Use paper wraps or compostable bags with cloth or brown paper.

Improvement of the environment on plastic ban:

  • Improve the health of individuals.
  • Driving to innovate alternatives.
  • Plastic pollution reduced.
  • The nation is safe.

X. Value-Based Questions

Question 1.
Why is it not possible to use solar cells to meet our energy needs? State three reason to support to your answer.
Answer:
In solar cells, the solar panel convert solar energy into electricity, which stored in storage battery. The storage battery gives direct current, which is to be converted into alternating current by an suitable appliances before it can be used to run various, devices. So, it increases the cost of using panels as the source of energy.

In the solar cells the energy is obtained only during the day, when the sun shines. So the solar cells is not used to meet our energy needs.

Question 2.
How would you dispose of the following wastes?

  1. Domestic wastes like vegetable peels
  2. Industrial wastes like metallic cans

Can the disposal protect the environment? How?
Answer:

  1. Domestic wastes have to be thrown out with the trash.
  2. Do vermiform composting system for vegetable wastes which can be used as a manure. Industrial wastes like metallic cans can be recycled.

Question 3.
List any three activities based on 3R approach to conserve natural resources.
Answer:
Recycling : Using recycled material of glass plastic, paper, metal etc.
Reuse : Repeating use of items.
Reduce : Avoid the use of materials which increases the solid waste.
Use of public transport instead of personal transport to reduce to consumption of fuel. Use of materials such as paper should be preferred.

Textbook Activities Solved

Question 1.
Collect information regarding the
(i) Tehri Dam project
(ii) Sardar Sarovar Dam project
Answer:
(i) Tehri Dam project:
Tehri Dam is the highest dam in India and one of the highest in the world. It is a multi-purpose rock and earth-filled embankment dam on the Bhagirathi River near Tehri in Uttarakhand, India. It is the primary dam of the THDC India limited and the Tehri hydro-electric complex. The Tehri Dam withholds a reservoir for irrigation, municipal water supply and the generation of 1000 megawatts of hydroelectricity.

(ii) Sardar Sarovar dam project:
Sardar Sarovar Dam is a gravity dam on the Narmadha river near Navagam. It is a part of the Narmada valley project, a large hydraulic engineering project.
Benefits:

  • Provides irrigation facilities.
  • Drinking water supply.
  • There are two powerhouses, red bed powerhouse and canal head powerhouse with a capacity of 1200 MW and 250 MW, respectively.
  • It provides flood protection.
  • Wildlife sanctuaries are maintained.
  • Development of fisheries.
  • Water supply for industries.
  • Protection of conserved forests.

Samacheer Kalvi 10th Science Environmental Management Additional Questions Solved

I. Fill in the blanks.

Question 1.
______ is used for generation of _____, at thermal power plants.
Answer:
Coal, Electricity

Question 2.
Petroleum is refined to produce _____ and _____, which are used to run automobiles, trucks, trains and ships, etc.
Answer:
Petrol, Diesel

Question 3.
______ and ______ obtained from petroleum are used as domestic fuel.
Answer:
Kerosene, LPG

Question 4.
Solar energy is obtained from ______
Answer:
Sun

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Question 5.
Solar cells convert sunlight directly into ______
Answer:
Electricity

Question 6.
_______ plants convert the kinetic energy of flowing water into electricity.
Answer:
Hydropower

Question 7.
The 3R approach such as _____, _____ and ______ may be followed to effective waste management.
Answer:
Reduce, Reuse and Recycle

Question 8.
_______ is a reserved area for the conservation of entire wildlife including plants and animals.
Answer:
National park

Question 9.
______ is a place reserved exclusively for the use of animals.
Answer:
Sanctuary

Question 10.
Unwanted, non-working and out-dated electronic products become ______
Answer:
e-waste

Question 11.
In India, the forests are classified into ______ forests and ______ forests.
Answer:
Reserved, Protected

Question 12.
The small ponds to collect rainwater is called ______
Answer:
Ooranis

II. Write true or false for the following statements. Correct the false statements:

Question 1.
Conservation of natural resources makes an important contribution to the social and economic development of the country.
Answer:
True

Question 2.
Overexploitation and shrinking of forest resulted, the increase of animals and the nourishment of wildlife.
Answer:
False
Correct statement: Overexploitation and shrinking of forest resulted, in animals becoming extinct, some are threatened and some are on the verge of extinction.

Question 3.
The potential energy possessed by the wind, due to lower speed, that can be converted into chemical power by wind turbines.
Answer:
False
Correct statement: The kinetic energy possessed by the wind is due to its high speed, that can be converted into mechanical power by wind turbines.

SamacheerKalvi.Guru

Question 4.
The main purpose of rainwater harvesting is to make the rainwater, run on its surface of Earth.
Answer:
False
Correct statement: The main purpose of rainwater harvesting is to make the rainwater, to percolate under the ground, so as to recharge the groundwater level.

Question 5.
The burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature is called electronic wastes.
Answer:
False
Correct statement: The burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature is called incineration.

III. Match the following:

Question 1.

1. Van Mahotsav (a) Destruction of forests
2. Bombay Natural History Society (b) Crude oil
3. Deforestation (c) Photovoltaic devices
4. Erosion (d) Afforestation programme
5. Solar cells (e) Conservation of wildlife
6. Petroleum (f) Removal of an upper layer of soil

Answer:

  1. (d) Afforestation programme
  2. (e) Conservation of wildlife
  3. (a) Destruction of forests
  4. (f) Removal of an upper layer of soil
  5. (c) Photovoltaic devices
  6. (b) Crude oil

IV. Choose the correct answer:

Question 1.
The new sources of energy are termed as _______
(a) fossil fuel
(b) Conventional energy resources
(c) Non-conventional sources of energy
(d) conservation
Answer:
(c) non-conventional sources of energy

Question 2.
Disposable plastic plates should not be used because:
(a) They are made of materials with light weight
(b) They are made of toxic materials.
(c) They are made of biodegradable materials.
(d) They are made of non-biodegradable materials.
Answer:
(d) They are made of non-biodegradable materials.

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Question 3.
The other name for Biogas is ______
(a) Natural gas
(b) Nitrogen gas
(c) Gobar gas
(d) Shale gas
Answer:
(c) Gobar gas

Question 4.
Wildlife includes:
(a) Wild animals only
(b) Wild plants only
(c) Wild plants and animals
(d) All plants and animals
Answer:
(d) All plants and animals

Question 5.
E-wastes are generally called as _______
(a) garbages
(b) electronic waste
(c) decomposition
(d) solid wastes
Answer:
(b) electronic waste

V. Answer the following shortly.

Question 1.
Why should we conserve forests and wild life?
Answer:
We should conserve forest and wild life to preserve the biodiversity, so as to avoid the loss of ecological stability. Without proper management of forest and wild life, the quality of soil, the water sources, and even the amount of rainfall may be affected.

Question 2.
What are the effects of deforestation?
Answer:
Deforestation gives rise to ecological problems like floods, drought, soil erosion, loss of wildlife, extinction of species, imbalance of biogeochemical cycles, alteration of climatic conditions and desertification.

Question 3.
Name the organisation involved in wild life conservation.
Answer:
Organisations Involved in Conservation of Wildlife

  1. Indian Board for WildLife (IBWL)
  2. World Wildlife Fund (WWF) for Nature
  3. World Conservation Union (WCN) ,
  4. International Union for Conservation of Nature and Natural resources (IUCN)
  5. Convention of International Trade in Endangered Species (CITES)
  6. Bombay Natural History Society
  7. Wild life Preservation Society of India, Dehradun

Question 4.
What are fossil fuels? How are they formed?
Answer:
The fossil fuels are petroleum, coal and natural gas. Due to the anaerobic decomposition of buried dead organisms, by a natural process over millions of years, energy-rich substances are formed. As the accumulating sediment layers produce heat and pressure, the remains of the organisms are gradually transformed into hydrocarbons.

SamacheerKalvi.Guru

Question 5.
Write the uses of solar cells.
Answer:

  1. It can be used for street lighting, traffic signals, water pumping, battery charging system etc.
  2. It is used in artificial satellites and space probes.
  3. It provides radio and TV transmission to remote areas.
  4. It is used in calculators, electronic toys and watches.

Question 6.
Write short notes about shale gas.
Answer:
Due to the compaction of small old rocks, which contain mud and minerals such as quartz and calcite, trapped beneath Earth’s surface and form the soft finely stratified sedimentary rock called shale. These rocks contain fossil fuels like oil and gas in their pores. This fuel is extracted by a technique called hydraulic fracturing.

Shale drilling could affect groundwater reserves, which can contaminate drinking water. It also affects the fertility of the soil. A million gallons of water is needed to break and release the shale gas which in turn can affect the fertility of the soil.
A million gallons of water is needed to break and release the shale gas, which in turn can affect the water table.

Question 7.
What is Tidal energy? What is it’s advantages?
Answer:
The energy obtained from the movement of water, due to ocean tides is called tidal energy. Tides are the rise and fall of sea level, caused by the combined effects of the gravitational force. A tidal stream is a fast-flowing body of water created by tides. Turbines are placed in tidal streams. When the tides hit the turbine, the turbine rotates and converts the tidal energy into electric energy.
Advantages:

  • It does not produce any pollution.
  • It does not use any fuel and does not produce any waste.
  • Tides are predictable, so tidal energy can be produced at any time.
  • Water is denser than air and therefore can generate electricity at lower speeds than wind turbines.

Question 8.
How is electric energy conserved?
Answer:

  • Use energy-efficient appliances to save electricity like compact fluorescent lamps (CFL), Light Emitting Diode [LED] bulbs and other electrical equipment.
  • Switch off the lights and fans, television and other electrical appliances, when not in use.
  • Switch off the mobile phone chargers when not in use.
  • Use more off solar radiation. Solar water heating system can be used instead of electric geysers.
  • Minimise the use of air conditioners.

Question 9.
What are the sources of e-waste? What is the environmental impact of e-waste?
Answer:
E-wastes are called electronic wastes, which includes the spoiled, outdated; non-repairable electrical and electronic devices. These wastes contain toxic metals like lead, cadmium, chromium and mercury, and also contains iron, copper, silicon, aluminium and gold, which can be recovered. The sources of e-wastes are:

  • Electronic device: Computers, laptops, mobile phones, printers, monitors, televisions, DVD players, calculators, toys and sports equipment.
  • Household electrical appliances: Refrigerators, washing machine, microwave oven, mixer, grinder and water heater, etc.
  • Accessories: Printing cartridges, batteries and chargers.

Environmental impact of e-wastes:
Disposal of any kind of electrical and electronic devices without knowledge can become the landfill and water pollutants.
Electronic equipment contains many heavy metals such as lead and cadmium that can cause severe soil and groundwater pollution. E-waste dumping yards and the places, nearby are polluted and cause a severe health hazard.

Question 10.
What is the 3R approach of ineffective waste management?
Answer:
Reduce, Reuse and Recycle are the 3R approach for effective waste management. Reducing the amount of waste, we produce is the best way to help the environment. Buying products with minimum packaging, not borrowing things which we do not use often, starting a compost bin, saving energy and water by turning are ways to reduce. Reuse materials in their original form or pass those materials on to others, who could use them. Paper cardboard, metals, plastics and textiles, etc can be recycled. The compost or reuse of bio-degradable wastes is also a kind of recycling.

SamacheerKalvi.Guru

Question 11.
What are non-conventional energy resources? What does it include?
Answer:
The energy resources available in an unlimited amount in nature and they can be renewed over a short period of time, inexpensive and can be harvested continuously is called the non-conventional energy resources.

The non-conventional energy resources include biofuel, bio mass-energy, geothermal energy, water energy (hydroelectric energy and tidal energy), solar energy, wave energy and wind energy.

Question 12.
What is the composition of Bio-gas? How is it formed?
Answer:

  • Bio-gas is the mixture of methane (75%), hydrogen sulphide, carbon dioxide and hydrogen.
  • It is produced by the decomposition of animal wastes (cow dung) and plant wastes in the ‘ absence of oxygen.
  • It is also commonly called as “Gobar gas”, as the starting material used is cow dung, which ~ means gobar in Hindi.

Question 13.
What are hydropower and hydropower electricity?
Answer:
Earth is covered with 71% of water. The technique to harness the water energy, from the flowing water is called the hydropower.

The electrical energy is derived from water flow and water falling from a height. In hilly areas, there is a continuous flow of water in large amounts falling from high slopes. The electricity produced by flowing water is called hydropower electricity.

VII. Answer the following in detail.

Question 1.
What are the aims of wildlife management?
Answer:
The main aim of wildlife conservation are:

  1. To control and limit exploitation of species.
  2. To preserve the plants and animals from extinction.
  3. Maintenance of threatened species and protect species which are on the verge of extinction.
  4. Preserve the endangered species.
  5. To study the ecological relationship of the plants and animals in natural habitat.
  6. Hunting and poaching should be prohibited.
  7. Establishment of National parks, Wildlife sanctuaries, protected areas and Biosphere reserves.

Question 2.
Explain in detail the classification of energy resources.
Answer:
Energy resources can be classified as renewable and non-renewable.
(i) Non-renewable (exhaustible) energy resources:
The energy obtained from sources that cannot renew themselves over a short period of time is called non-renewable energy. They include coal, petroleum, natural gas and nuclear power. The conventional energy resources account for 90% of the world’s production of commercial energy and nuclear power account for 10%.

(ii) Renewable (inexhaustible) energy resources:
Renewable (inexhaustible) energy resources are available in the unlimited amount in nature and they can be renewed over a short period of time, inexpensive and can be harnessed continuously. These are called non-conventional energy resources, which include biofuel, biomass energy, geothermal energy, water energy (hydroelectric energy and tidal energy), solar energy, wave energy and wind energy.

Question 3.
Write a note an shale gas. Explain the environment impact of shale gas.
Answer:
Shale refers to the soft finely stratified sedimentary rock that is formed from the compaction of small old rocks containing mud and minerals – such as quartz and calcite, trapped beneath earth’s surface. These rocks contain fossil fuels like oil and gas in their pores.

The fuel is extracted by a technique called hydraulic fracturing (drilling or well boring of sedimentary rocks layers to reach productive reservoir layers).

Environmental concerns of shale gas:

  1. Shale drilling could affect groundwater reserves, which can contaminate the drinking water resources and also affect the fertility of the soil.
  2. Million gallons of water is needed to break and release the shale gas, which intum can affect the water table.

Question 4.
(a) How does windmill work?
(b) List out the uses of wind energy and the advantages of wind energy.
Answer:
(a) A windmill is a machine, that converts the energy of wind, into rotational energy by broad blade attached to the rotating axis. When the blowing air strikes the blades of the windmill, it exerts force and causes the blades to rotate. The rotational movement of the blades operate the generator and the electricity is produced. The energy output from each windmill is coupled together to get electricity on a commercial scale.

(b) The uses of wind energy are as follows:

  • Generating electricity.
  • Run water pumps and flour mills, etc.
  • Rotatory motion of windmill is used to draw water from wells.

Advantages of wind energy:

  • Wind energy is a free, eco-friendly and renewable source of energy.
  • It does not cause pollution.
  • Expenses on periodic maintenance are low when compared to the other power sources.

Question 5.
(a) What are the sources of sewage or wastewater?
(b) Expiate the methods which involve in conventional wastewater treatment.
Answer:
(a) The sources of sewage or wastewater involve:

  • The domestic purpose or household activities
  • Dye and textile industries
  • Leather industries
  • Sugar and breweries industries
  • Paper and pulp industries

(b) The conventional wastewater treatment methods involve the following step:

  • Pre-screening: Wastewater generated from domestic and industrial activities is screened to remove soil and solid particulates.
  • Aeration: Screened wastewater is pumped to an aeration tank. Here the microbial contaminants are removed by the biological degradation, that occurs, in the presence of air.
  • Sedimentation process: In this process, the solid particles in suspension form are allowed to settle. The particles that settle out from the suspension is known as sludge.
  • Sludge removal: The sludge generated by the degradation process is transferred periodically from the tank for safe disposal.
  • Disinfection: Chlorination and ultraviolet (UV) radiation of treated water is required to remove any microorganism contamination.
  • Water recycling: The water will then be supplied for domestic or industrial purposes.

Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management 1

VII. Higher Order Thinking Skills (HOTS) Questions

Question 1.
There are certain NGOs which ask people to donate their used clothes, toys, school books, house hold items. These NGOs segregate the collected items and distribute them to the needy people. What objectives do these NGOs fulfil by this initiatives?
Answer:
The objective behind this is Reuse and Recycle.

Question 2.
Name the national park, which was first established at Uttarakhand.
Answer:
Jim Corbett national park.

Question 3.
An environmentalist on your visit to your school suggested the use of 3R’s to same the environment. Explain the 3R’s.
Answer:
The 3R’s are Reduce, Reuse and Recycle.
Reuse : Instead of throwing thing away, try to find ways to use them again.
Recycle : Creating new product out of the materials from the old.
Reduce : It is the best way to help the environment by reducing the amount of waste you produce.

Question 4.
Where does India stand at the consumer of crude oil?
Answer:
India is the third-largest consumer of crude oil in the world after the United States and China.

Question 5.
Why does the white marble of Tajmahal become yellow?
Answer:
The Mathura oil refinery owned by Indian Oil Corporation presents around this area, which produces sulphur and nitrogen oxides. The white marble became yellow due to air pollution. The Government of India has set up emission standards around the monument to protect it from the damage.

Question 6.
Name the fourth oldest dam in the world? Where is it located?
Answer:
Kallanai Dam, which is also Called Grand Anicut, is the fourth oldest dam in the world. The dam is located on the river Kaveri, 20 km from the city of Tiruchirappalli.

Question 7.
Where is the world’s largest and tallest wind turbine located?
Answer:
The world’s largest and tallest wind turbine is situated in Hawai. One wind turbine can produce electricity for 300 homes.

SamacheerKalvi.Guru

Question 8.
Name the health effects of the following E-wastes.
Answer:

  • Lead: Damages the central and peripheral nervous system. It also affects brain development in children.
  • Chromium: Asthmatic bronchitis.
  • Cadmium: Accumulates in kidney and liver; Neural damage.
  • Mercury: Chronic damage to the brain and respiratory system.
  • Plastics including polyvinyl chloride [PVC]: Burning produces, dioxin, which can cause developmental and reproductive problems and damage the immune system.

Samacheer Kalvi 10th Science Solutions Chapter 22 Environmental Management Read More »

Samacheer Kalvi 10th English Letter Writing

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Letter Writing

Letters are the most common forms of written communication. Writing letters is an art and it is mastered through practice. We write letters to friends and relatives to maintain contacts with them. However, in the present times with the boom in methods of communication, many of us don’t have the time or the inclination, or the temperament and the art to write letters.

So telephone, fax, and e-mail have replaced personal (informal) letters. However, formal ‘ letters are still in vogue. Commerce, trade, official correspondence, public representation, complaints, and other dealings, transactions, and communication with the people are still (conducted through letters. Students are therefore advised to cultivate the art and skill of letter writing. It must be remembered that different kinds of letters follow different conventions. So, the format should suit the type.

Samacheer Kalvi 10th English Letter Writing

INFORMAL LETTERS
These are ordinary personal letters and informal invitations written to relatives, friends, and acquaintances. The main characteristics of informal letters are:

  • These letters are first/second person presentations.
  • Personal feelings and emotions find an expression,
  • The writer’s address is given in the usual place.
  • The salutation is usually‘Dear’plus name’.
  • The date of writing is given, but the year is generally omitted.
  • The style and tone are relaxed and informal.
  • Different tenses are used as sense demands.
  • The complimentary close is: ‘Yours lovingly’or‘Yours truly’.

FORMAL LETTERS
A formal letter is different from a personal letter in tone and content. These letters are written for official purposes or commercial correspondence, so they must be systematic, specific in content and formal in treatment of the subject. The main features of formal letters are:

  • The matter is brief, clear and to the point.
  • There are separate paragraphs for separate topics.
  • The first paragraph indicates the theme of the letter,
  • The facts are stated in simple and direct language.
  • Long and high sounding words are avoided.
  • Even while lodging a complaint or making a criticism, the tone should be polite.
  • Clumsy expressions should not be used.
  • The complimentary close is: ‘Yours sincerely’, or ‘Yours faithfully’.

FORMAT/LAYOUT OF A FORMAL LETTER
08th March, 20XX
From
XXX
Sender’s Address & Phone No.

To
THE DIRECTOR
Addressee’s Address
……………………………….
……………………………….

Respected Sir/Madam,
SUB: Frequent Power Failure

Body of the Letter

Thank you,
Yours sincerely,
XXX

To
The Director
……………………………….
……………………………….

Note: There is no punctuation after From and To Thank you has been used instead of Thanking you

Samacheer Kalvi 10th English Letter Writing

Types Of Formal Letters
A. BUSINESS LETTERS

  • Making enquiries/asking for information
  • Replying to enquiries/giving information
  • Placing orders and sending replies
  • Cancelling orders
  • Letters of complaints

B. OFFICIAL LETTERS

  • Registering complaints regarding civic amenities, law & order, etc.
  • Making inquiries pertaining to development projects, health facilities, etc.
  • Making requests/appeals

C. LETTER TO THE EDITOR

  • Giving suggestions on an issue (usually of public interest)
  • Expressing views on an issue already raised in an article/write – up/in a published letter

D. LETTER OF APPLICATION

  • Applications for jobs

Solved Questions
Informal Letter
(i) Write a letter to your mother informing her that your vacations will be starting on 15th April and will reach home on 16th of April.
Answer:

Chennai
02.04.2020

Dear mother,
I’m fine. I hope all are fine at home. My vacations are starting on the 15th of April and I’ll reach home the next day. Please prepare my favorite dishes mom. Counting days to be home. Love you ma.

Yours lovingly,
XYZ

To
Mrs. Malathi
12, MG Road,
Trichy

(ii) Radhika has got success in NEET. She wants to celebrate her admission to Shivaji Medical College, Nagpur by throwing a party to her friends. Help her write an informal invitation giving details of venue, time and date. Do not exceed 50 words.

18, Natesan Street,
T. Nager,
15th July, 20XX

Dear Vaishali,
You will be glad to learn that I have secured 80th rank in the NEET competition. I have got admission in a prestigious institution – Shivaji College, Nagpur. I want to share a few happy moments of my life in the company of my old friends at a dinner in the Hotel GRT grand days T. Nagar at 8.00 p.m. on 23 July, 20XX.

Please join the celebrations and merry-making.

Yours sincerely,
Radhika.

Address on the envelope
D. Vaishali D/O Krishnan,
18, VOC Street,
Vandalur.

(iii) Raju’s parents have completed 25 years of happy married life. Help him to invite his aunt, living in Kalayarkovil, to join him in the Silver Jubilee celebration of their marriage at his residence.

245, Greenway Road,
Chennai.
25th March, 2020

Respected Aunt,
My parents Sh. R.S. Swaminathan and Smt. Parvathi Devi will be completing 25 years of their happy, prosperous and eventful married life next month. We are going to celebrate the Silver Jubilee of their married life on 5th May, 2016. It will be a simple ceremony. Only family members and close friends are invited.

Do join us on this auspicious day.

Yours sincerely,
S. Raju.

Address on the envelope
Mrs. Leela, W/o Soundar,
8, Car St,
Kalayar Kovil.

Formal Letter Letter Of Request
(i) Madhu/Rajesh Dharmapuri is a student of class 10th. Write a letter to the Principal, Sishya Matriculation School, Dharmapuri, requesting him A her to open a career counseling center in the school to help and guide the students in the choice of subjects at + 2 level as well as at college level and to give other valuable advice/suggestions. Help him/her to complete the letter.

From
Madhu / Rajesh
51, Main Road,
Dharmapuri.
16th March, 2020

To
The Principal,
Sishya Matriculation School,
Dharmapuri.

sir,
Sub: Request to open a career counselling centre.

I am a student of class X in your school and is currently appearing for the Board examination. Very soon, we will have to make an important decision. We will have to select the stream/ subjects we should opt for at the +2 level. As you know, this is the most crucial decision of a student’s life. Most of the parents are unaware of the latest trends in educational/job fields. I, therefore, request you to kindly open a career counselling centre in our school to help us make the correct choice according to our aptitudes/talents as well as future job prospects. Expert guidance in the field will prove invaluable to us.

I hope you will consider my request favourably.

Thank you

Yours faithfully,
Madhu / Rajesh

Address on the envelope
The Principal,
Sishya Matriculation School,
Dharmapuri

Samacheer Kalvi 10th English Letter Writing

(ii) You are Raja/Vaishnavi, Head Boy/Girl of your school. Help him/her in writing to arrange extra classes in Maths for the students of X classes. Give detailed reasons to support your demand.
Answer:

12 March, 20XX

From
Raja / Vaishnavi,
X A Student ABC Hr. Sec. School,
XYZ City.

To
The Principal,
ABC Hr. Sec. School,
XYZ City

Sir,
Sub: Extra Classes in Maths

The other day we were admonished about the poor performance in Maths in the Revision Examination. We have tried to search our souls, rack our brains and find out the fault. The reason is quite obvious. Our Maths teacher retired in August and stop-gap arrangements were made for three months by appointing temporary hands. Only last month we were able to get guidance from an expert and competent teacher like Mr. Murthy. However, a lot of our course remains uncovered and proper justice cannot be done to it in the regular periods only. Moreover, we have to make up the time-lapse. Drill, revision, and classroom tests also require certain periods. In view of the paucity of time available to us between now and the commencement of board examination, it is requested that some extra classes before/after school hours be arranged in Maths for Std. X.

I hope that the request of the students will be acceded to without any delay.

Thank you

Yours obediently,
Raja/Vaishnavi.
Head boy / Head Girl.

Address on the envelope
The Principal,
ABC Hr. Sec. School, XYZ City

Complaint Letter

(iii) You are Pramila of 32,3rd main road, Adyar, Chennai. Last week, you bought a mobile phone from ‘The Mobile Junction’, 20N, Muthulakshmi street, Chennai. The mobile phone developed a problem within a few days of its purchase. Write a complaint letter to the dealer giving details of the nature of the problem and asking him/her to rectify the defect or replace the phone.

Ms. Pramila
32, 3rd main road
Adyar
Chennai

29 April, 20XX
The Sales Manager
The Mobile Junction
20N, Muthulakshmi street
Chennai

Sir,
Sub: Defective Mobile Phone

I am a resident of Adyar, Chennai. I purchased a Samsung 4G mobile phone from The Mobile Junction on 22nd April, 20XX, vide cash memo No. 14219/18.1 am sorry to say that the mobile phone developed a problem within a few days of its purchase. The sound system is quite irritating and jarring. The camera doesn’t give a clear and deep impression. I feel cheated to have such a defective mobile phone after spending more than fifteen thousand rupees. It is quite unfortunate that even after sending two reminders, you have shown no urgency to rectify the defects or replace the defective mobile set at the earliest. I hope you will do the needful within a week. I am sure you will not compel me to knock the doors of the Consumer Court for this unpleasant lapse of time on your part.

Yours sincerely
Pramila

To
The Sales Executive
The Mobile Junction
20N, Muthulakshmi street
Chennai

Samacheer Kalvi 10th English Letter Writing

(iv) You are R. M. Sridharan, the Head Librarian of M.G. Sr. Secondary School, Thuthukudi. Write a letter to Mrs. Atma Ram & Sons, Guwahati, complaining about the poor quality of books supplied to your library. You can invent your own details.
Answer:
R. M. Sridharan
M.G. Sr. Secondary School
Thuthukudi
25 March, 20XX
M/s Atma Ram & Sons
23, Fancy Bazar
Thuthukudi

Sir,
Sub: Poor quality of books ‘

We need no introduction. We are old customers of Atma Ram & Sons. But, I am constrained to express my displeasure at the poor and substandard supply of books by you in response to our order.
On examination, the following obvious discrepancies were found in the books supplied by you;

  1. 40 textbooks of Mathematics by R.K. Sharma are of 20XX (old) edition. While these books are available in the latest 20XX editions in the market.
  2. We ordered for 30 books of History of Ancient India by L.K. Gupta. However, we have been supplied with the books of the same title written by R.K– Gupta.
  3. Some books are not in good and proper condition and can’t be accepted as such.

We hope you will do the needful without any further delay and replace them with their latest editions and in proper conditions.

Yours sincerely
R.M. Sridharan
(Head Librarian)
Enel. – Photocopy of the book – list.

To
M/s Atma Ram & Sons
23, Fancy Bazar
Thuthukudi

(v) Write a letter to the Station House Officer of Mattencheri Police Station in Cochin complaining him about the bad law and order situation in your area. You can give concrete and useful suggestions to protect and safeguard the interests of school and college going girls and senior citizens. You can invent your own details.
Answer:
James Mathews
4/12, Mattencheri Street
Cochin
10 March 20XX The S.H.O.
Mattencheri Police Station
Cochin

Sir,
Sub: Protecting female students and senior students from lawlessness

It pains me to express my strong resentment and anguish against the bad law and order situation prevailing in Mattencheri Residential Colony of Cochin.

Bad law and order situation has become an integral part of Mattencheri’s social and cultural scene. The recent day – light robberies and murders have sent a shockwave among the residents of the area. I would like to highlight the routine and regular harassment faced by the female students near their schools. In spite of the legal ban, wine shops do exist just in front of schools. Drunkards indulge in teasing and assaulting school girls. Even the kidnapping of a minor school girl last week didn’t arouse the conscience of the law and order authorities. It is not only the job of the administration to open new schools for girls but also their primary responsibility to provide them a safe journey from their house to their schools. All wine shops near school should be closed immediately. The bad characters and teasers must be given exemplary punishments. Senior citizens must be given a special protection. Complete records of maid servants and helpers must be maintained in the concerned police stations.

The need of the hour is to take effective and prompt actions to maintain peace and harmony in the area.

Yours faithfully
James Mathews

To
The S.H.O.
Mattencheri Police Station
Cochin

Samacheer Kalvi 10th English Letter Writing

(vi) You are Anuradha, the Head Girl of Swami Vivekanand Sr. Secondary School, Patna. You are distressed at the unhygienic conditions in the school toilets. Even the classrooms remain dusty and dirty. Write a letter to the Principal of your school, complaining him of this unfortunate situation. Also give suggestions to improve the condition.
Answer:
Anuradha
X B, Swami Vivekanand Sr. Secondary School
Chennai
12 June 20XX
The Principal
Swami Vivekanand Sr. Secondary School
Chennai

Sir,
Sub: Unclean toilets and classrooms
On behalf of all students of classes IX and X, I want to bring to your notice the unhygienic conditions of the toilets in the school. Even the classrooms remain dusty and dirty for days together. The toilets in the school stink badly. It needs a lot of patience to go and use them. One can use them only by putting one’s handkerchief over the nose. The flushing system generally remain out of order. Most of the urine pots are broken. The leaked urine flows on the floor causing a nauseating odour. The condition of the classrooms is not much better. They are not swept or cleaned daily. A layer of dust and dirt gathers over the benches and desks. To be brief, such unhygienic conditions don’t go with this illustrious institution. They bring a bad name and create a bad impression on the outsiders. I hope that you will take some prompt action to improve the situation drastically in the near future.

Yours obediently
Anuradha
Head Girl
Class X

To ,
The Principal
Swami Vivekanand Sr. Secondary School
Chennai

Letter Of Enquiry

(vii) Write a letter seeking detailed inquiries from the General Manager, Holiday Inn, Puducherry for conducting the wedding reception of your younger brother at the hotel. Make specific inquiries about the catering cost per head, service and decoration charges. You can also ask for the advance amount to be paid. You are Krishna/Kamini.
Answer:
House No. 43/4
Civil Lines
Puducherry
20 May 20XX
The General Manager
Holiday Inn
Puducherry

Sir,
Sub: Enquiring about rates for wedding reception

The wedding reception of my younger brother, Mukesh will be solemnized on 20 June 20XX. We want to hold the ceremony and the wedding reception at your hotel. The party may include about 300 heads, including children. We would like to book four rooms in the hotel for the guests also. The ceremony may continue up to the early hours of 23rd June, 20XX.

Kindly furnish the following details regarding the reception function:

  • Catering cost per head with menu details
  • Service charges
  • Decoration charges (stage and mandap)
  • Room charges
  • Advance money to be paid

We would appreciate if you send any other relevant information concerning the wedding reception.

Yours truly
Krishna/Kamini

To
The General Manager
Holiday Inn
Puducherry

Letter Of Placing Order

Samacheer Kalvi 10th English Letter Writing

(viii) You are Laxman/Laxmi, the Head Librarian of Rammanna Public School, Nellore. Write a letter to Janta Book Depot, Nellore placing bulk order for books needed for the school library. You can invent your own details.
Answer:
The Head Librarian
Ramanna Public School
Nellore
12th July, 20XX
Sales Manager
Janta Book Depot
Nellore

Dear Sir
Sub: Order for books
We received the quotations sent by you regarding the purchase of books for the school library. We are glad to inform you that we have found your quotations acceptable to us. We welcome the 20% discount that you are providing on the books in general. However, we would expect a special discount that some dealers are providing on the bulk purchases for the educational institutions.

The list of books with their particulars are attached here with.

Name Author/Publisher Copies Required
A Comprehensive Grammar of the English Language Quick & Leech Pearson Pub. 40
The Fall of Roman Empire Gibbon 40
Arabian Nights Harper & Collins 30
Stories for Children Rupa & Co. 50
Fables National Book Trust 50
Wonder That was India Bhasham 30
Shakespeare’s Complete Works Penguin 50
Mathematics for All Bansi Lai 60
History of Ancient India R.K. Sharma 30
Chemistry for Schools M. L. Soni 30
Physics for Schools Ghanshyam Das 30
Prem Chand Ki Kahania Prem Chand National Book Trust 50
Nirala R. B. Sharma 30

Books must be in their latest editions and delivered in good condition.

Yours truly
Laxman/Laxmi
Head Librarian

To
Sales Manager
Janta Book Depot
Nellore

Letter Of Cancelling Order
(ix) You are Ramkumar, Sales Manager of Modern Dresses, Madurai. You placed a bulk ’order with Shobha Dresses, Madurai for the supply of Gowns for your showroom. The firm has failed to execute the order. In spite of our many reminders, there is no positive response from them. Write a letter to the firm that you are constrained to cancel the order that you had placed before.
Answer:
K. Raman
Modem Dresses
TVS Nagar
Madurai
25th September, 2020
M/s Shobha Dresses Pandian Nagar Madurai

Dear Sirs,
Sub: Order for Gowns – Cancellation
I can express only my deep dismay and displeasure at the non – execution of the bulk order that we placed with you for the purchase of gowns on 10th August, 2020. The said order was to be executed within 10 days. However, when more than a month expired, you expressed regrets giving the strike of workers in the factory as the main reason of non – execution. We accepted your request for executing the order within a week. We condoned the delay keeping in view of our previous good business terms. As we have not heard from you recently, we have reasons to believe that cancellation of the said order is the only option for us. I hope that the cancellation of the said order will not affect our otherwise good business terms in future.

Yours faithfully
K. Ramkumar

To
M/s Shobha Dresses
Pandian Nagar
Madurai

Letter To The Editor
(x) The tourism industry can bring valuable income to the country. Write a letter to the Editor of a popular daily on how the government and the public can boost the development of this industry. You are Rama/Ram, 4 Rani Road, Tiruchirappalli.
Answer:
Ram
4, Rani Road
Tiruchirappalli
20 April 20XX

The Editor
The Hindustan Times
Tiruchirappalli

Sir,
Sub: Boosting tourism industry in India
Through the column of your esteemed daily, I want to highlight the tremendous potentiality that the tourism industry has in India. The tourism industry can easily be a money-spinner as it can bring valuable income to the country. Let’s first explore the new avenues for international tourists in India. It has been a great shame for us that India has not been even among the top ten in the international market. We have breathtaking views of the Himalayas, beautiful valleys, wonderful hill stations, very rich wildlife, including the tiger and the rhino reserves. India can boast of fascinating beaches in Goa and Kerala. We have the Taj Mahal and the Fatehpur Sikri in Agra; Madurai and Tanjavur in Tamil Nadu; Sanchi in MP and Nalanda in Bihar. The ghats of Varanasi and feudal splendors of Rajasthan need no introduction. Only we will have to revamp our strategies. We will have to re – woo our tourists. Instead of running after the recession hit western Europe and America, we must explore new avenues in China, Russia, and Brazil. China attracts 50.9 million tourists every year. India manages just 5.1 million tourists. We will have to fill up the gap.

Domestic tourism can’t be neglected. States like Karnataka and Kerala have shown the way to the other states of India. They have attracted budget domestic tourists by providing clean and affordable accommodation. Enhanced infrastructure, such as good roads, airports and good hygiene will attract more international as well as domestic tourists. Surely, tourism industry can bring valuable income to the country.

Thank you

Yours sincerely
Ram

To
The Editor
The Hindustan Times
Tiruchirappalli

Samacheer Kalvi 10th English Letter Writing

(xi) You are Santhanam/Sapna. You are a regular visitor to the Prasad Nagar Lake. Of late, residents of the colony have been disturbed by the constant flow of foul-smelling water in the lake garden and generally failing cleanliness standards. Taking hints given in the input below, along with your own details, write a letter to the Editor of a local daily emphasizing the urgent need to improve the hygienic conditions of the park.
Answer:
Santhanam/Sapna
12, Swami Nagar
Prasad Nagar
Mysore
12 April 20XX

The Editor
The Deccan Herald
Bangalore

Sir,
Sub: Unhygienic conditions of Prasad Nagar Lake and its surroundings
Through the column of your esteemed daily, I express my anguish at the deterioration of Prasad Nagar Lake and its surroundings.
There was a time when Prasad Nagar Lake and its surroundings were considered to be the most beautiful spot in the area. It is a pity that within a decade everything has reached a stage of decay and deterioration. I am a regular visitor to the lake. Of late, residents of the colony have been disturbed by the constant flow of foul-smelling water into the lake garden. This has been caused due to the repeated bursting of a sewer line running next to the lake garden. The foul-smelling water accumulates and stagnates in the lake. This has resulted in a heavy presence of algae in the lake. It has hampered the boating facilities provided here by the authorities. The state of fish farming is quite deplorable.

I hope this letter will arouse the concerned authorities out of their hibernation. They must take immediate and effective steps to bring the lake and its surroundings back to its former grandeur and glory.

Thank you

Yours faithfully
Santhanam/Sapna

Samacheer Kalvi 10th English Letter Writing

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Samacheer Kalvi 10th English Construction of Dialogues

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Construction of Dialogues

1. Frame a dialogue with a minimum of ten exchanges for the given situation:
Between a doctor and a patient

Patient : Good Morning, Doctor!
Doctor : Good Morning! Any problem?
Patient : I am feeling a great pain on my left shoulder.
Doctor : I shall check your BP. (Checks up blood pressure and there is nothing wrong)
Patient : What’s wrong with me?
Doctor : Nothing to worry much. I guess there is some block in your heart.
Patient : What? What should I do now?
Doctor : Don’t panic. We will take an Angiogram.
Patient : Why not X-ray Doctor?
Doctor : Arteries are invisible to X – rays. A color dies passing through veins shows where the block is.

Samacheer Kalvi 10th English Construction of Dialogues

2. Frame a dialogue with a minimum of ten exchanges for the given situation:
Between a Policeman and a tourist who needs some guidance

Tourist : Excuse me, Sir.
Police : Yes. how can I help you?
Tourist : Thank you, Sir. I just need to know how to get to Chennai Airport.
Police : It is just five kilometers from here. By what mode do you plan to go?
Tourist : I shall take a bus.
Police : Then cross the road to the opposite side. Take bus route No. 18G.
Tourist : Does the bus stop right at the Airport?
Police : Yes, right in front of the airport at Tirisulam stop.
Tourist : Thank you very much Sir. Very kind of you.
Police : You’re most welcome.

3. Frame a dialogue with a minimum of ten exchanges for the given situation:
Build up a dialogue between two friends regarding the use of plastics

Arun : Hello.
Binu : Hello.
Arun : It seems you are on your way to the bazaar.
Binu : Quite right. How do you know?
Arun : The cloth bag in your hand of course.
Binu : Your guess is absolutely right.
Arun : I have n’t brought any. The shopkeeper will give carry bags.
Binu : Yes, but they are plastic or polythene. We should not use them.
Arun : Why? What’s wrong?
Binu : Plastic bag pollutes the soil. It is non-biodegradable. Clothe bag is simple but biodegradable.
Arun : Thank you. I will carry a cloth bag hereafter.

4. Frame a dialogue with a minimum of ten exchanges for the given situation:
Between a Post Master and a student who wants to open a savings account in the post office.

Student : Good morning sir.
PM : Good morning. What shall I do for you?
Student : Sir, I want to open a savings account.
PM : Have you brought your Aadhar card?
Student : Yes, sir.
PM : Have you brought two copies of passport size photograph of yourself?
Student : Yes sir.
PM : Fill in this application. How much do you wish to deposit now?
Student : Rs. 500/ – Sir.
PM : That is good to start with.
Student : Thank you sir.

Samacheer Kalvi 10th English Construction of Dialogues

5. Frame a dialogue with a minimum of ten exchanges for the given situation:
Between a mother and her daughter, discussing the daughter’s first salary day

Daughter : Hi, Mom!
Mother : Hi dear!
Daughter : Mom, I have a lot to tell you.
Mother : Tell me. Why are you late?
Daughter : I went to buy some thing for you and dad.
Mother : So, you bought a saree for me and clothes for dad.
Daughter : Yes Mom. But you look upset.
Mother : That’s nothing. We counted on your salary to pay your brother’s term fees.
Daughter : You did not even open the parcel.
Mother : Sorry dear, show me. Wow! How nice they are.

6. Frame a dialogue with a minimum of ten exchanges for the given situation:
Between two brothers/sisters discussing the job they would like to take up when they are older.

Manju : Now let us discuss what we want to be in future.
Mala : Okay. First you tell what you want to be?
Manju : I would like to pursue medicine.
Mala : I want to be an Engineer.
Manju : The country has enough engineers. There is a very poor health care
delivery system. So, I want to serve the poor.
Mala : If you take up medicine, your marriage will be delayed.
Manju : Don’t worry. Goal of life is not marriage my dear. It will happen when it has to.
Mala : Wish you Good luck.
Manju : Thanks, wish you the same.
Mala : Hope we both realize our dreams.

7. Frame a dialogue with a minimum of ten exchanges for the given situation:
Build a dialogue between a mother and her daughter, discussing the daughter’s first day in her new school.

Sudha : Hi, Mom.
Mother : Hi dear! How was your first day in school?.
Sudha : Mom, I have a lot to tell you about that.
Mother : Tell me. Why is your uniform stained?
Sudha : We had a drawing period Mom.
Mother : So, you stained your uniform. Go and change the dress.
Sudha : Okay
Mother : Why are you sad?
Sudha : You did not appreciate my drawing. My whole class gave me a standing ovation.
Mother : Sorry dear, show me. Wow! How lovely!

Samacheer Kalvi 10th English Construction of Dialogues

8. Frame a dialogue with a minimum of ten exchanges for the given situation:
Build a conversation between a Headmaster and an old student who has come to get a testimonial from the Headmaster

Old student : Good Morning, sir!
Headmaster : Good Morning, Hemant! How are you and what are you doing now?
Old student : Sir, I have just finished my graduation and I am looking for a job.
Headmaster : That’s good. What brings you here?
Old student : Sir, I have received an interview call from a leading software company for the post of Software Engineer. They are asking me to furnish a testimonial from you.
Headmaster : Can you meet me tomorrow? I shall keep it ready.
Old student : Sure, sir. I will meet you tomorrow. Good Day, Sir!
Headmaster : Okay. Have a great day.

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Samacheer Kalvi 10th English Expand The News Headlines

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Expand The News Headlines

1. Over 300 Political Party Workers Arrested
Bangalore: Over 300 political party workers, on the charges of instigating violence, in the disturbed areas of Mandya were arrested yesterday. They were arrested when they blocked traffic on the Bengaluru – Mysuru highway in Mandya town. However, they were released later.

2. SBI’s new rules
Savings bank account holders in SBI having more than Rs 1 lakh balance will earn a quarter percentage point less interest from Wednesday. The interest rate on such balances will go up in case the Reserve Bank hikes Repo rate.

Samacheer Kalvi 10th English Expand The News Headlines

3. Evidence of new solar system found
Using NASA’s Kepler space telescopes, astronomers have uncovered enticing evidence of what could be the first discovery of a moon orbiting a planet outside our solar system. Researchers caution that the moon hypothesis is tentative and must be confirmed by follow – up Hubble observations. ‘If confirmed, this finding could completely shake up our understanding of how moons are formed and what they can be made of’, said Astronomer Hamilton Kingham meeting the press persons this evening.

4. Ahead of polls, IT raids carried out in Chennai
Chennai: With just a few days left for the elections in Tamil Nadu, a team of officials from the IT department carried out raids in various places in Chennai.

5. Cops chase down bike on fire, save lives of three
Chennai : A bag attached to the bike, which had three people on it, caught fire on Chennai – Ennore highway. A police van noticed the fire when the bike crossed the police car on a national highway. The police van chased them and helped douse the fire.

6. Old Man Scales Everest
An 85 – year – old Chinese man who began the year with his fourth heart operation has become the oldest conqueror of Mount Everest, a feat he called “the world’s best feeling”, even with an 81 – year – old Nepalese climber not far behind him. “We have arrived at the summit,” Mr. Minura, pictured, said from the world’s highest point. The world’s most incredible mountaineering team had helped him to accomplish this feat.

7. Bomb Explodes – Children injured
Two children were seriously injured in a crude bomb explosion in Trichy’s suburban area. The explosion was reported in a farm in the outskirts of Trichy. The investigation in the crude bomb explosion is underway. The crude bomb exploded near a coconut grove where some children were playing in the evening.

8. Jet puts off date to resume foreign flights
New Delhi : Jet Airways has stopped accepting bookings for its Mumbai – Paris flight until June 10 and closed reservations for its Mumbai – London, Mumbai – Amsterdam – Mumbai and Bangalore – Amsterdam flights, up to July 18.

Samacheer Kalvi 10th English Expand The News Headlines

9. Scorched Delhi to witness light rain
New Delhi : After waking up to a cloudy Friday morning with light rain, residents of Delhi and the National Capital Region (NCR) can expect a dry weekend. However, according to the India Meteorological Department (IMD), thunderstorms and light rain can be expected at the start of next week.

10. Fleming: Will take call on MS Dhoni’s participation against Delhi Wednesday
Chennai : Chennai Super Kings head coach Stephen Fleming said that MS Dhoni had been “pretty sick” last week but is progressing good. A call on his participation in the game against Delhi Capitals on Wednesday will be taken before the toss.

11. Man Killed In Accident
Punjab : The local people have booked an unidentified person after a man from Bhadson was killed in a road accident in Bakhshiwala village here on Thursday. The deceased has been identified as Jaswant Singh. The police said as per the complainant, Inderjeet Singh, an ’unidentified person rammed his car into the motorcycle of Jaswant Singh, leaving him spot dead. A case has been registered.

Samacheer Kalvi 10th English Expand The News Headlines

12. Ustad Shujaat Husain Khan: The melody maker
Noida : One of the greatest living legends of sitar, Khan, who is part of the HCL Mega Concert 2019, says classical music is an experience you need to be open to. The HCL Mega Concert, held in Delhi, Noida and Gurugram, witnessed a wide range of music genres, including fusion and pure classical music jugalbandis. He’s observed at least 50 percent of the audience being under the age of 25 and therefore feels that his efforts have clearly paid off.

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Samacheer Kalvi 10th English Poster Making

You can Download Samacheer Kalvi 10th English Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Attempt all english grammar practice sections covered in the Samacheer Kalvi 10th English Grammar Book and excel in reading, writing, and speaking english with great fluency.

Tamilnadu Samacheer Kalvi 10th English Poster Making

Posters are placards displayed in a public place announcing or advertising something. Posters are notices, advertisements, and invitations – all in one.

Purpose
The purpose of designing’ a poster is either to create social awareness about issues related to current problems and needs or to advertise or even to extend public invitations and display notices.

Drafting
Posters should be colorful, attractive and tempting.

  1. They must be drafted carefully to attract the attention of the readers, excite their imagination and influence their minds.
  2. Posters are read from a distance. Do not give many details in a poster. Highlight only important issue/issues.

Samacheer Kalvi 10th English Poster Making

Main Features
(i) Layout

  • Visually attractive/Eye Catching
  • Title—suggestive/catchy
  • Use slogan, jingle or short verse
  • Sketch or simple drawings
  • Letters of different size and shape
  • Proportionate spacing, etc.

(ii) Contents

  • The theme or subject of the poster
  • Description or details associated with the theme
  • Essential details like time, date, venue (for an event)
  • Name (s) of issuing authority/organisation, etc.

(iii) Expression

  • Phrases, slogans, persuasive language
  • Creativity in terms of content and design
  • Overall organisation and sequencing of the matter

Solved Questions
1. Design a poster for your School Fete. You may use slogans. Do not exceed 50 words.
Answer:
Samacheer Kalvi 10th English Poster Making 1

2. Design a poster in not more than 50 words for your school library on the value of books and good reading habits. You may use slogans.
Answer:
Samacheer Kalvi 10th English Poster Making 2

Samacheer Kalvi 10th English Poster Making

3. As the President of Leo Club of Temple Town, prepare a poster on behalf of Lions Club and Leo Club for ‘Diwali Mela’ to be held at Nehru Stadium, mentioning some of the attractions
Answer:
Samacheer Kalvi 10th English Poster Making 3

4. Healthy sea food – BBQ and grill – Attractive, 20% discount on week days – at Chetpet – Contact 43374747 or 28364040.
Answer:
Samacheer Kalvi 10th English Poster Making 4

5. Health mela organised by Red Cross Society at Island Grounds & Invent other details.
Answer:
Samacheer Kalvi 10th English Poster Making 5

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Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology

You can Download Samacheer Kalvi 10th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology

Samacheer Kalvi 10th Science Breeding and Biotechnology Textual Evaluation Solved

I. Choose the Correct Answer.

Question 1.
Which method of crop improvement can be practised by a farmer if he is inexperienced?
(a) clonal selection
(b) mass selection
(c) pure line selection
(d) hybridisation.
Answer:
(a) clonal selection

Question 2.
Pusa Komai is a disease resistant variety of:
(a) sugarcane
(b) rice
(c) cow pea
(d) maize
Answer:
(c) cow pea

Question 3.
Himgiri developed by hybridisation and selection for disease resistance against rust pathogens is a variety of ______.
(a) chilli
(b) maize
(c) sugarcane
(d) wheat.
Answer:
(d) wheat.

SamacheerKalvi.Guru

Question 4.
The miracle rice which saved millions of lives and celebrated its 50th birthday is:
(a) IR 8
(b) IR 24
(c) Atomita 2
(d) Ponni
Answer:
(a) IR 8

Question 5.
Which of the following is used to produce products useful to humans by biotechnology techniques?
(a) enzyme from organism
(b) live organism
(c) vitamins
(d) both (a) and (b).
Answer:
(d) both (a) and (b).

Question 6.
We can cut the DNA with the help of:
(a) scissors
(b) restriction endonucleases
(c) knife
(d) RNAase
Answer:
(b) restriction endonucleases

Question 7.
rDNA is a ______.
(a) vector DNA
(b) circular DNA
(c) recombinant of vector DNA and desired DNA
(d) satellite DNA.
Answer:
(c) recombinant of vector DNA and desired DNA

Question 8.
DNA fingerprinting is based on the principle of identifying sequences of DNA:
(a) single-stranded
(b) mutated
(c) polymorphic
(d) repetitive
Answer:
(d) repetitive

Question 9.
Organisms with a modified endogenous gene or a foreign gene are also known as ______.
(a) transgenic organisms
(b) genetically modified
(c) mutated
(d) both (a) and (b).
Answer:
(a) transgenic organisms

Question 10.
In hexaploid wheat (2n = 6x = 42) the haploid (n) and the basic(x) number of chromosomes are:
(a) n = 7 and x = 21
(b) n = 21 and x = 21
(c) n = 1 and x = 1
(d) n = 21 and x = 7
Answer:
(d) n = 21 and x = 7

II Fill in the blanks.

Question 1.
Economically important crop plants with superior quality are raised by ______.
Answer:
Breeding.

Question 2.
A protein rich wheat variety is ______.
Answer:
Atlas 66.

SamacheerKalvi.Guru

Question 3.
_______ is the chemical used for doubling the chromosomes.
Answer:
Colchicine.

Question 4.
The scientific process which produces crop plants enriched with desirable nutrients is called ______.
Answer:
Biofortification.

Question 5.
Rice normally grows well in alluvial soil, but _____ is a rice variety produced by mutation breeding that grows well in saline soil.
Answer:
Atomita – 2 rice

Question 6.
_____ technique made it possible to genetically engineer living organism.
Answer:
Recombinant DNA.

Question 7.
Restriction endonucleases cut the DNA molecule at specific positions known as ______.
Answer:
Molecular scissors.

Question 8.
Similar DNA fingerprinting is obtained for ______.
Answer:
Identical twins.

Question 9.
______ cells are undifferentiated mass of cells.
Answer:
Pleuripotent.

Question 10.
In gene cloning, the DNA of interest is integrated in a ______.
Answer:
Vector [plasmid].

III. State whether true or false. If false, write the correct statement.

Question 1.
Raphano brassica is a man – made tetraploid produced by colchicine treatment.
Answer:
True.

SamacheerKalvi.Guru

Question 2.
The process of producing an organism with more than two sets of chromosome is called mutation.
Answer:
False.
Correct statement: The process of producing an organism with more than two sets of chromosome is called polyploidy.

Question 3.
A group of plants produced from a single plant through vegetative or asexual reproduction are called a pureline.
Answer:
False.
Correct statement: A group of plants produced from a single plant through vegetative or asexual reproduction are called clones.

Question 4.
Iron fortified rice variety determines the protein quality of the cultivated plant.
Answer:
False.
Correct statement: Iron fortified rice variety determines the iron quality of the cultivated plant.

Question 5.
Golden rice is a hybrid.
Answer:
False.
Correct statement: Golden rice is a genetically modified plant.

Question 6.
Bt gene from bacteria can kill insects.
Answer:
True.

Question 7.
In vitro fertilisation means the fertilisation done inside the body.
Answer:
False.
Correct statement: In vitro fertilisation means the fertilisation done outside the body.

Question 8.
DNA fingerprinting technique was developed by Alec Jeffrey.
Answer:
True.

Question 9.
Molecular scissors refers to DNA ligases.
Answer:
False.
Correct statement: Molecular scissors refers to Restriction Enzymes.

IV. Match the following:

Question 1.

Column A Column B
1. Sonalika (a) Phaseolus mungo
2. IR-8 (b) Sugarcane
3. Saccharum (c) Semi-dwarf wheat
4. Mung No. 1 (d) Groundnut
5. TMV-2 (e) Semi-dwarf Rice
6. Insulin (f) Bacillus thuringienesis
7. Bt toxin (g) Beta carotene
8. Golden rice (h) the first hormone produced using rDNA technique

Answer:

  1. (c) Semi – dwarf wheat
  2. (e) Semi – dwarf Rice
  3. (b) Sugarcane
  4. (a) Phaseolus mungo
  5. (d) Groundnut
  6. (h) the first hormone produced using rDNA technique
  7. (f) Bacillus thuringienesis
  8. (g) Beta carotene.

V. Understand the assertion statement, justify the reason given and choose the correct choice:

(a) The assertion is correct and the reason is wrong.
(b) Reason is correct and the assertion is wrong.
(c) Both assertion and reason are correct.
(d) Both assertion and reason are wrong.

Question 1.
Assertion: Hybrid is superior to either of its parents.
Reason: Hybrid vigour is lost upon inbreeding.
Answer:
(a) The assertion is correct and the reason is wrong.

Question 2.
Assertion: Colchicine reduces the chromosome number.
Reason: It promotes the movement of sister chromatids to the opposite poles.
Answer:
(d) Both assertion and reason are wrong.

SamacheerKalvi.Guru

Question 3.
Assertion: rDNA is superior over hybridisation techniques.
Reason: Desired genes are inserted without introducing the undesirable genes in target organisms.
Answer:
(c) Both assertion and reason are correct.

VI. Answer in a Sentence

Question 1.
Give the name of the wheat variety having higher dietary fibre and protein.
Answer:
Atlas 66, a protein-rich variety, having higher dietary fibre and protein.

Question 2.
Semi-dwarf varieties were introduced in rice. This was made possible by the presence of dwarfing gene in rice. Name this dwarfing gene.
Answer:
Dee-geo-woo-gen a dwarf variety from China.

Question 3.
Define genetic engineering.
Answer:
Genetic engineering is the manipulation and transfer of genes from one organism to another organism to create a new DNA called recombinant DNA (rDNA). Genetic engineering is also called recombinant DNA technology.

Question 4.
Name the types of stem cells.
Answer:
Embryonic stem cells and somatic stem cells are the types of stem cells.

Question 5.
What are transgenic organisms?
Answer:
Plants or animals expressing a modified endogenous gene or a foreign gene are called transgenic organisms.

Question 6.
State the importance of biofertiliser.
Answer:
Biofertilizer adds nutrients through the natural process of nitrogen fixation, stimulate the plant growth through the synthesis of growth-promoting substance.

VII. Short Answer Questions

Question 1.
Discuss the method of breeding for disease resistance.
Answer:
Plant diseases are caused by pathogens like viruses, bacteria and fungi. This affects crop yield. To develop disease-resistant varieties of crops, that would increase the yield and reduce the use of fungicides and bactericides are important. Some disease-resistant varieties are as follows:

Crop Variety Resistance to diseases
Wheat Himgiri Leaf and stripe rust, hill bunt
Cauliflower Pusa Shubhra, Pusa Snowball K-1 Black rot
Cowpea Pusa Komal Bacterial blight

Question 2.
Name three improved characteristics of wheat that helped India to achieve high productivity.
Answer:
Sonalika, kalyan and sona are the three improved characteristic of wheat that helped India to achieve high productivity.

SamacheerKalvi.Guru

Question 3.
Name two maize hybrids rich in amino acid lysine.
Answer:
Protina, Shakti and Rathna are lysine – rich maize hybrids, which are developed in India.

Question 4.
Distinguish between
(a) Somatic gene therapy and germline gene therapy.
(b) Undifferentiated cells and differentiated cells.
Answer:
(a) Somatic gene therapy and germline gene therapy.

Somatic gene therapy Germline gene therapy
Somatic gene therapy is the replacement of the defective gene in somatic cells. Germline gene therapy is the replacement of the defective gene in the germ cell (egg and sperm).

(b) Undifferentiated cells and differentiated cells.

Undifferentiated cells Differentiated cells
Our body is composed of over 200 specialised cell types, that can carry out specific functions, eg. Neurons or nerve cells that can transmit signals. Pancreatic cells to secrete insulin. These specialised cells are called as differentiated cells. The cells which are variable potency, undifferentiated or unspecialised mass of cells are called stem cells. The stem cells are undifferentiated or unspecialised mass of cells.

Question 5.
State the applications of DNA fingerprinting technique.
Answer:
Applications of DNA Fingerprinting:
(i) DNA fingerprinting technique is widely used in forensic applications like crime investigation such as identifying the culprit. It is also used for paternity testing in case of disputes.
(ii) It also helps in the study of genetic diversity of population, evolution and speciation.

Question 6.
How are stem cells useful in the regenerative process?
Answer:
Sometimes cells, tissues and organs in the body may be permanently damaged or lost due to genetic condition or disease or injury. In such situations, stem cells are used for the treatment of diseases, which is called stem – cell therapy. In treating neurodegenerative disorders like Parkinson’s disease and Alzheimer’s disease neuronal stem cells can be used to replace the damaged or lost neurons.

Question 7.
Differentiate between outbreeding and inbreeding.
Answer:
Inbreeding:
When breeding or mating takes place between animals of the same breed, for about 4 – 6 generations, then it is called inbreeding. Superior males and superior females of the same breed are identified and mated in pairs. It helps in the accumulation of superior genes and the elimination of undesirable genes. Inbreeding depression is the continued inbreeding, which reduces fertility and productivity. Inbreeding exposes harmful recessive genes that are eliminated by selection.
Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology 1
Outbreeding:
The breeding of unrelated animals is outbreeding. The offsprings formed are called hybrids. The hybrids are stronger and vigorous than their parents. Cross between two different species with desirable features of economic value is mated. Mule is superior to the horse in strength, intelligence, ability to work and resistance to diseases, but they are sterile.

VIII. Long Answer Questions

Question 1.
What are the effects of hybrid vigour in animals.
Answer:

  1. Increased production of milk by cattle.
  2. Increased production of egg by poultry.
  3. High quality of meat is produced.
  4. Increased growth rate in domesticated animals.

Question 2.
Describe mutation breeding with an example.
Answer:
The mutation is defined as the sudden heritable change in the nucleotide sequence of DNA in an organism. The genetic variations brings out changes in an organism. The organism which undergoes mutation is called a mutant.
The factors which induce mutations are known as mutagens or mutagenic agents. The mutagens are of two types:
(a) Physical mutagens: Radiations like X – rays, a, P and Y – rays, UV rays and temperature, etc, which induce, maturations are called physical mutagens.

(b) Chemical mutagens: Chemical substances that induce mutations are called chemical mutagens, eg. Mustard gas and nitrous acid. The utilization of induced mutation in crop improvement is called mutation inbreeding.
Achievements of mutation breeding:

  • Sharbati Sonora wheat produced from Sonora – 64 by using gamma rays.
  • Atomica – 2 rice with saline tolerance and pest resistance.
  • Groundnuts with thick shells.

Question 3.
Biofortification may help in removing hidden hunger. How?
Answer:
Biofortification: Biofortification is the scientific process of developing crop plants enriched with high levels of desirable nutrients like vitamins, proteins and minerals. Some examples of crop varieties developed as a result of biofortification are given below:

  1. Protina, Shakti and Rathna are lysine rich maize hybrids (developed in India).
  2. Atlas 66, a protein rich wheat variety.
  3. Iron rich fortified rice variety’.
  4. Vitamin A enriched carrots, pumpkin and spinach.

Question 4.
With a neat labelled diagram explain the techniques involved in gene cloning.
Answer:
The carbon copy or more appropriately, a clone means to make a genetically exact copy of an organism. ‘Dolly’ is the cloned sheep.
Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology 2
In gene cloning, a gene or a piece of DNA fragment is inserted into a bacterial cell, where DNA will be multiplied (copied) as the cell divides.
The basic steps involved in gene cloning are:

  • Isolation of desired DNA fragment by using restriction enzymes.
  • Insertion of the DNA fragment into a suitable vector (plasmid) to make rDNA.
  • Transfer of rDNA into the bacterial host cell (Transformation).
  • Selection and multiplication of the recombinant host cell to get a clone.
  • Expression of the cloned gene in the host cell.

Using this strategy several enzymes, hormones and vaccines can be produced.

Question 5.
Discuss the importance of biotechnology in the field of medicine.
Answer:
Using genetic engineering techniques medicinally important valuable proteins or polypeptides that form the potential pharmaceutical products for the treatment of various diseases have been developed on a commercial scale.
Pharmaceutical products developed by rDNA technique:

  1. Insulin used in the treatment of diabetes.
  2. Human growth hormone used for treating children with growth deficiencies.
  3. Blood clotting factors are developed to treat haemophilia.
  4. Tissue plasminogen activator is used to dissolve blood clots and prevent heart attack.
  5. Development of vaccines against various diseases like Hepatitis B and rabies.

IX. Higher Order Thinking Skills (HOTS) Questions

Question 1.
A breeder wishes to incorporate desirable characters into the crop plants. Prepare a list of characters he will incorporate.
Answer:
The list of character he will incorporate are:

  1. High yielding and better quantity
  2. Disease resistance
  3. Insects pest resistance
  4. Improved nutritional quality
  5. Short duration

Question 2.
Organic farming is better than Green Revolution. Give reasons.
Answer:

  • Dwarfness is desired in cereals, so fewer nutrients are consumed by the crops.
  • Fertilizer is responsive.
  • Disease resistant varieties.
  • Insect and pest resistant crop varieties.
  • High levels of desirable nutrients like vitamins, proteins and minerals.

Question 3.
Polyploids are characterised by gigantism. Justify your answer.
Answer:
An organism having more than two set of chromosome is called polyploidy. It can be induced by physical agents such as heat or cold treatment, X-rays and chemical agents like colchicine. As organisms produced by polyploidy have more than two set of chromosomes they are gigantic.

Question 4.
‘P’ is a gene required for the synthesis of vitamin A. It is integrated with the genome of ‘Q’ to produce genetically modified plant ‘R’.
(i) What is P, Q and R?
(ii) State the importance of ‘R’ in India.
Answer:
(i)  The P, Q and R:

  • P – Beta – carotene gene.
  • Q – Prevent vitamin A deficiency.
  • R – Golden rice.

(ii) Importance of rice in India:

  • Rice is the most important staple food for millions of people in developing countries like India.
  • Beta – carotene is produced in the endosperm of the grain. It could control the chronic health problems caused by vitamin A deficiency, especially among the poor in developing countries like India.

Samacheer Kalvi 10th Science Breeding and Biotechnology Additional Questions Solved

I. Fill in the blanks.

Question 1.
Plant ______ is the art of developing economically important plants.
Answer:
Breeding.

Question 2.
Plant diseases are caused by ______ like viruses, bacteria and fungi.
Answer:
Pathogen.

Question 3.
______ is the first man – made cereal hybrid.
Answer:
Triticale.

Question 4.
The superiority of the hybrid obtained by cross-breeding is called _____ or ______.
Answer:
Heterosis
or
Hybrid vigour.

SamacheerKalvi.Guru

Question 5.
The other name for genetic engineering is ______.
Answer:
Recombinant DNA technology.

Question 6.
The organism which undergoes mutation is called a ______ and the factors which induce mutations are ______.
Answer:
Mutant; mutagenic agents.

Question 7.
The replacement of the defective gene in a germ cell (egg or sperm) is called ______.
Answer:
Germline gene therapy.

Question 8.
Blood clotting factors are developed to treat ______.
Answer:
Haemophilia.

Question 9.
Stem cells, which are undifferentiated or unspecialised mass of cells can be used for the treatment is called ______.
Answer:
Stem cell therapy.

Question 10.
_______ is used in the treatment of diabetes.
Answer:
Insulin.

II. Match the following:

Question 1.

1. Cowpea (a) Joining the DNA fragments
2. UV rays (b) New breed of sheep
3. Lady’s finger (c) Bacterial blight
4. DNA ligase (d) Flat bean
5. Pusasem 3 (e) Pusa Sawani
6. Hissardale (f) Induce mutation

Answer:
1. (c) Bacterial blight
2. (f) Induce mutation
3. (e) Pusa Sawani
4. (a) Joining the DNA fragments
5. (d) Flat bean
6. (b) New breed of sheep.

III. Write “True or False” statements. Correct the false statements:

Question 1.
Modem Agricultural practices are activities carried out to improve the plants.
Answer:
True.

Question 2.
When breeding takes place between animals of the same breed, it is called outbreeding.
Answer:
False.
Correct statement: When breeding takes place between animals of the same breed, it is called inbreeding.

Question 3.
The process of introducing high yielding varieties of plants from one place to another is called a selection.
Answer:
False.
Correct statement: The process of introducing high yielding varieties of plants from one place to another is called Exotic species.

SamacheerKalvi.Guru

Question 4.
The mutation is a sudden inheritable change in the nucleus sequence of DNA in an organism.
Answer:
False.
Correct statement: Mutation is a sudden heritable change in the nucleotide sequence of DNA in an organism.

Question 5.
A breed is a group of animals of common origin within a species, which has certain characters, that are not found in other members of the same species.
Answer:
True.

IV. Choose the correct answer.

Question 1.
The high yielding rice variety from Indonesia and China are ______.
(a) Peta and DGWG
(b) IR-8 and Gold rice
(c) Hexaploid Triticale and Triticum durum
(d) Sonalika and Kalyan Sona.
Answer:
(a) Peta and DGWG

Question 2.
First artificially synthesized hormone is:
(a) Secretin
(b) Insulin
(c) Glucagon
(d) Renin
Answer:
(b) Insulin

Question 3.
The presence of this substance in bacteria can undergo replication independently along with chromosomal DNA ______.
(a) heritable
(b) colchicine
(c) mutation
(d) plasmid.
Answer:
(d) plasmid.

Question 4.
Bacillus thuringiensis (Bt) stains have been used for designing novel.
(a) Bio-metallogical techniques
(b) Bio-insecticidal plants
(c) Bio-mineralization
(d) Bio-fertilizer
Answer:
(b) Bio-insecticidal plants

Question 5.
A group of plants produced from a single plant through vegetative or asexual reproduction is called ______.
(a) Transgenic
(b) Hexaploid
(c) clones
(d) mutation.
Answer:
(b) Hexaploid

V. Answer the following briefly:

Question 1.
What is the green revolution? Who is the “Father of Green Revolution”?
Answer:
Green Revolution is the process of increasing food production through high yielding crop varieties and modem agricultural techniques in underdeveloped and developing nations. Dr Norman. E. Borlaug, an American agronomist is the “Father of Green Revolution”.

Question 2.
Write the role of polyploidy in crop improvement.
Answer:
The role of polyploidy in crop improvement are production of:

  1. Seedless watermelons (3n) and bananas (3n).
  2. TV-29 (triploid variety of tea) with larger shoots and drought tolerance.
  3. Triticale (6n) is a hybrid of wheat and rye. To make this plant fertile polyploidy is induced. It has higher dietary fibre and protein.
  4. Raphanobrassica is an allotetraploid by colchicine treatment.

Question 3.
What is Bio – fortification? Give any two examples.
Answer:
Bio – fortification is the scientific process of developing crop plants enriched with high levels of desirable nutrients like vitamins, proteins and minerals.
Examples of crop varieties developed as a result of bio – fortification are:

  • Protina, Shakti and Rathna are lysine – rich maize hybrids.
  • Atlas 66, A protein – rich wheat variety.

Question 4.
Give two examples of cross-breeding in animals.
Answer:
Cross breed of fowls: White Leghorn X Plymouth Rock

Hybrid fowl – yield more eggs

Cross breed of cows : Developed by mating the bulls of exotic breeds and cows of indigenous breeds.
Brown Swiss X Sahiwal

Karan Swiss – yield 2-3 times more milk than indigenous cows.

Question 5.
What is hybridization? Explain the hybridization experiment.
Answer:
The process of crossing two or more types of plants for bringing their desired characters together into one progeny hybrid is called hybridization. Hybridization is creating a genetic variation to get improved varieties.

Hybridization Experiment:
Triticale is the first man-made cereal hybrid. It is obtained by crossing wheat (Triticum durum, 2n = 28) and rye (Secale cereal, 2n = 14). The F, a hybrid is sterile (2n = 21). Then the chromosome number is doubled using colchicine and it becomes hexaploid triticale (2n = 42). The cycle of crop raising and selection continues until the plants with the desired characters are finally obtained.

SamacheerKalvi.Guru

Question 6.
Name the methods of plant breeding for crop improvement.
Answer:
The methods of plant breeding to develop high yielding varieties, for crop improvement, are as follows:

  • Introduction of new varieties of plants
  • Selection
  • Polyploid breeding
  • Mutation breeding
  • Hybridization.

Question 7.
Explain briefly about gene therapy.
Answer:
The replacement of a defective gene by the direct transfer of functional genes into humans to treat genetic disease or disorder is referred to as gene therapy.
The recombinant DNA technology is used for gene therapy:

  • Somatic gene therapy is the replacement of the defective gene in somatic cells.
  • Gene line gene therapy is the replacement of the defective gene in the germ cell (egg or sperm).

Question 8.
What were the important discoveries that led to the stepping stones of recombinant DNA technology?
Answer:

  1. Presence of plasmid in bacteria that can undergo replication independently along with chromosomal DNA.
  2. Restriction enzymes cuts or break DNA at specific sites and are also called as molecular scissors.
  3. DNA ligases are the enzymes which help in ligating (joining) the broken DNA fragments.

Question 9.
What does modern agriculture include?
Answer:
Modem agricultural practices are activities carried out to improve the cultivation of plants. It includes:

  1. Preparation of soil
  2. Sowing
  3. Application of manures and fertilizers
  4. Proper irrigation
  5. Protection from weeds and pests
  6. Harvesting and threshing
  7. Storage

Question 10.
What is the aim of crop improvement?
Answer:
The aim of crop improvement is to develop improved crop varieties possessing higher yield, better quality, resistance to diseases and shorter duration.

Question 11.
(a) What are the two important properties of stem cells?
(b) Write a short note on two types of stem cells.
Answer:
(a) Properties of stem cells:
It’s the ability to divide and give rise to more stem cells by self-renewal.
It’s the ability to give rise to specialised cells with specific functions by the process of differentiation.

(b) Types of cells:

  • Embryonic stem cells: Embryonic stem cells are derived from the inner cell mass of the blastocyst, which can be extracted from the early embryos. These cells can be developed into any cell in the body.
  • Adult stem cell or somatic stem cell: These cells are found in the newborn and adults. They have the ability to divide and give rise to specific cell types. Sources of adult stem cells are amniotic fluid, umbilical cord and bone marrow.

Question 12.
What are bulk genomic DNA and satellite DNA?
Answer:
In human beings, 99 % of the DNA base sequences are the same and this is called a bulk genomic DNA. The remaining 1 % of the DNA sequence differs from one individual to another. This 1 % DNA sequence is present as a small stretch of repeated sequences, which is called satellite DNA.

VI. Answer the following in detail.

Question 1.
What are stem cells? Explain its types.
Answer:
Stem cells are undifferentiated or unspecialised mass of cells. The stem cells are the cells of variable potency. The two important properties of stem cells that differentiate them from other cells are:

  1. Its ability to divide and give rise to more stem cells by self-renewal.
  2. Its ability to give rise to specialised cells with specific functions by the process of differentiation.

Types of stem cells Embryonic stem cells can be extracted and cultured from the early embryos. These cells are derived from the inner cell mass of the blastocyst. These cells can be developed into air, cell in the body.

Adult stem cell or somatic stem cell are found in the neonatal (new bom) and adults. They have tne ability to divide and give rise to specific cell types. Sources of adult stem cells are amniotic fluid, umbilical cord and bone marrow.

Question 2.
Explain with examples the inbreeding and outbreeding of animal breeding.
Answer:
Animal breeding aims at the genotypes of domesticated animals to increase their yield and improve the desirable qualities to produce milk, egg and meat. When breeding takes place between animals of the same breed, it is called inbreeding.
The cross between different – breeds is called outbreeding.
Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology 3
1. Inbreeding:
Inbreeding refers to the mating of closely related animals within the same breed for about 4 – 6 generations. Superior males and superior females of the same breed are identified and mated in pairs. It helps in the accumulation of superior genes and elimination of genes, which are undesirable. Hissardale is a new breed of sheep developed in Punjab by crossing Bikaneri (Magra) ewes and Australian Marino rams.

2. Inbreeding depression:
Continued inbreeding reduces fertility and productivity. Inbreeding exposes harmful recessive genes that are eliminated by selection.

3. Outbreeding:
It is the breeding of unrelated animals. The offsprings formed are called hybrids. The hybrids are stronger and vigorous than their parents. Cross between two different species with desirable features of economic value are mated. Let’s see what cross produce a mule. Mule is superior to a horse in strength, intelligence, ability to work and resistance to diseases but they are sterile
Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology 4

Question 3.
Explain the DNA fingerprinting technology with an illustration.
Answer:
The DNA pattern of two individuals cannot be the same except for identical twins. Each persons DNA sequence is unique, due to the small difference in the base pairs. DNA fingerprinting is the easier and quicker method, to compare the genetic difference among the two individuals. This technique was developed by Alec Jeffrey.

Each individual’s unique DNA sequences provides distinct characteristics of an individual, which helps in identification. A variable number of tandem repeat sequences [VNTRs] serve as molecular markers for identification.
Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology 5
In human beings, 99 % of DNA base sequences are the same and this is called as bulk genomic DNA. The remaining 1 % DNA sequence differs from one individual to another. This 1 % DNA sequence is present as a small stretch of repeated sequences which is called as satellite DNA. The number of copies of the repeat sequence also called VNTRs differs from one individual to another and results in variation in the size of the DNA segment.

As shown in the illustration, the sequence AGCT is repeated six times in the first person, five times in the second person and seven times in the third person. Because of this, the DNA segment of the third person will be larger in size followed by a DNA segment of first – person and then the second person. Thus it is clear that satellite DNA brings about variation within the population. Variation in the DNA banding pattern reveals differences among the individuals.

Question 4.
Write a detailed account of stem cells, types of stem cells and stem cell therapy?
Answer:
Our body is composed of over 200 specialised cell types, that can carry out specific functions, eg. Neurons or nerve cell that can transmit signals or heart cells which contract to pump blood or pancreatic cells to secrete insulin. These specialised cells are called differentiated cells. These specialised cells are called as differentiated cells. In contrast to differentiated cells, stem cells are the undifferentiated or unspecialised mass of cells. The stem cells are the cells of variable potency.
The two important properties of stem cells are:

  • its ability to divide and give rise to more stem cells by self-renewal,
  • its ability to give rise to specialised cells with specific functions by the process of differentiation.

Types of stem cells:

  1. Embryonic stem cells: These cells are extracted and cultured from the early embryos. These cells are derived from the inner cell mass of the blastocyst. These cells can be developed into any cell in the body.
  2. Adult stem cell or somatic stem cell: They are found in the neonatal (newborn) and adults. They have the ability to divide and give rise to specific cell types. The sources of adult stem cells are amniotic fluid, umbilical cord and bone marrow.
  3. Stem – cell therapy: Sometimes cells, tissues and organs in the body may be permanently damaged or lost due to genetic condition or disease or injury. In such situations, stem cells are used for the treatment of diseases, which is called stem cell therapy. In treating neurodegenerative disorders like Parkinson’s disease and Alzheimer’s disease neuronal stem cells can be used to replace the damaged or lost neurons.

Question 5.
(a) Explain genetically modified organisms |GMOs|.
(b) With the help of a tabular column tabulate the genetically modified plants and animals, with the objectives, gene inserted and achievement.
Answer:
(a) Genetic modification is the alteration or manipulation of genes in the organisms using rDNA techniques in order to produce the desired characteristics. The DNA fragment inserted is called transgene. Plants or animals expressing a modified endogenous gene or a foreign gene are also known as transgenic organisms.

The transgenic plants are much stable, with improved nutritional quality, resistant to diseases and tolerant to various environmental conditions. Similarly, transgenic animals are used to produce proteins of medicinal importance at low cost and improve livestock quality.

(b) Genetically modified plants and animals:
1. Genetically Modified Plants:

Objective Gene Inserted Achievement
Improved nutritional quality in Rice Beta carotene gene (In humans, Beta carotene is required for the synthesis of Vitamin A) Golden Rice (Genetically modified rice can produce beta carotene, that can prevent Vitamin A deficiency)
Increased crop production Bt gene from bacteria Bacillus thuringiensis. (Bt gene produces a protein that is toxic to insects) Insect resistant plants (These plants can produce the toxin protein that kills the insects which attack them)

2. Genetically Modified Animals:

Objective Gene inserted Achievement
The improved wool quality and production Genes for synthesis of amino acid, cysteine Transgenic sheep (gene expressed)
Increased growth in fishes Salmon or Rainbow trout or Tilapia growth hormone gene Transgenic fish (gene expressed)

VII. Higher Order Thinking Skills (HOTS) Questions

Question 1.
Name the Indian scientist who is known for his leading role in India’s green revolution.
Answer:
Dr M. S. Swaminathan.

Question 2.
The application of biotechnology ‘A’ to treat a person born with a hereditary disease.
(a) What does ‘A’ mean?
(b) Mention its types.
Answer:
(a) Gene therapy refers to the replacement of defective gene.
(b) The two type of gene therapy are Somatic and Germline.

SamacheerKalvi.Guru

Question 3.
Write the crossbreeds of the following:
(a) Crossbreed of fowls
(b) Crossbreed of cows
Answer:
(a) A crossbreed of fowls:

  • White Leghorn × Plymouth Rock

    Hybrid fowl – yield more eggs

(b) A crossbreed of cows:

  • Brown Swiss × Sahiwal

    Karan Swiss [yield 2 – 3 times more milk than indigenous cows]

Samacheer Kalvi 10th Science Solutions Chapter 20 Breeding and Biotechnology Read More »