Samacheer Kalvi 10th Science Solutions Chapter 21 Pdf

Samacheer Kalvi 10th Science Solutions Chapter 21 Pdf

Tamilnadu Board Samacheer Kalvi 10th Science Solutions Chapter 21: Tamilnadu State Board Solution Class 10 Science Chapter 21 – HEALTH AND DISEASES.

Samacheer Kalvi 10th Science Solutions Chapter 21: Overview


Samacheer Kalvi






Chapter Name


Samacheer Kalvi 10th Science Solutions Chapter 21 Pdf



Choose the correct answer


1> Tobacco consumption is known to stimulate secretion of adrenaline. The component causing this could be

  • a) Nicotine
  • b) Tannic acid
  • c) Curcumin
  • d) Leptin

Ans: a) Nicotine

Because, nicotine is a alkaloid present in tobacco which is highly harmful and poisonous substance.


2> World ‘No Tobacco Day’ is observed on

  • a) May 31
  • b) June 6
  • c) April 22
  • d) October 2

Ans: a) May 31

Because, May 31st is observed as No tobacco day i.e. World Anti-Tobacco Day.


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

Ans: d) Undergoing rapid division


4> Which type of cancer affects lymph nodes and spleen?

  • a) Carcinoma
  • b) Sarcoma
  • c) Leukemia
  • d) Lymphoma

Ans: c) Leukemia

Because, leukemia is characterized by an increase in the formation of white blood cells in the bone marrow and lymph nodes.


5> Excessive consumption of alcohol leads to

  • a) Loss of memory
  • b) Cirrhosis of liver
  • c) State of hallucination
  • d) Suppression of brain function

Ans: b) Cirrhosis of live


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

Ans: d) Insufficient blood supply to heart muscles

Because, insufficient blood supply to heart muscles causes coronary heart disease.


7> Cancer of the epithelial cells is called

  • a) Leukemia
  • b) Sarcoma
  • c) Carcinoma
  • d) Lipoma

Ans: c) Carcinoma

Because, Carcinoma arise from epithelial and glandular tissue.


8> Metastasis is associated with

  • a) Malignant tumour
  • b) Benign tumour
  • c) Both (a) and (b)
  • d) Crown gall tumour

Ans: a) malignant tumour

Because, metastasis is associated with malignant tumor.


9> Polyphagia is a condition seen in

  • a) Obesity
  • b) Diabetes mellitus
  • c) Diabetes insipidus
  • d) AIDS

Ans: b) Diabetes mellitus

Because, Polyphagia is a condition seen in diabetes mellitus.


State whether true or false, if false write the correct statement


1> AIDS is an epidemic disease.

Ans: False

Correct statement: AIDS is a viral disease.


2> Cancer causing genes are called Oncogenes.

Ans: True


3> Obesity is characterized by tumour formation.

Ans: Fasle

Correct statement: Obesity is characterized by an accumulation of excess body fat with an abnormal increase in body weight.


4> In leukemia both WBCs and RBCs increase in number.

Ans: False

Correct statement: Leukemia is characterized by an increase in the formation of white blood cells in the bone marrow and lymph nodes.


5> Study of cause of disease is called etiology.

Ans: False

Correct statement: Study of cause of the diseases is called Pathology.


6> AIDS is not transmitted by contact with a patient’s clothes.

Ans: True


7> Type 2 diabetes mellitus results due to insulin deficiency.

Ans: False

Correct statement: In type-2 diabetes mellitus, insulin production by the pancreas is normal but target cells do not respond to insulin.


8> Carcinogens are cancer causing agents.

Ans: True


9> Nicotine is a narcotic drug.

Ans: False

Correct statement: Nicotine is a stimulant, highly harmful and poisonous substance in tobacco.


10> Cirrhosis is associated with brain disorder.

Ans:  False

Correct statement: Liver damage resulting in fatty liver which leads to Cirrhosis and formation of fibrous tissue.


III. Expand the following abbreviations


IDDM: Insulin Dependent Diabetes Mellitus

HIV: Human Immunodeficiency Virus

BMI: Body Mass Index

AIDS: Acquired Immuno Deficiency Syndrome

CHD: Coronary Heart Disease

NIDDM: Non-Insulin Dependent Diabetes Mellitus


4> Match the following


  • Sarcoma: Connective tissue cancer
  • Carcinoma: Stomach cancer
  • Polydipsia: Excessive thirst
  • Polyphagia: Excessive hunger
  • Myocardial Infarction: Lack of blood flow to the heart muscle


5> Fill in the blanks

1> Cirrhosis is caused in liver due to excessive use of __________________

Ans: Cirrhosis is caused in liver due to excessive use ofalcohol.


2> A highly poisonous chemicals derived from tobacco is _________________

Ans:A highly poisonous chemicals derived from tobacco isnicotine.


3> Blood cancer is called ___________.

Ans: Blood cancer is called leukemia.


4> Less response of a drug to a specific dose with repeated use is called ________

Ans: Less response of a drug to a specific dose with repeated use is called tolerance.


5> Insulin resistance is a condition in _____________diabetes mellitus

Ans: Insulin resistance is a condition in type-2 diabetes mellitus.


6> Analogy type questions. Identify the first words and their relationship and suggest a suitable word for the fourth blank


  • Communicable: AIDS: Non communicable: Obesity
  • Chemotherapy: Chemicals: Radiation therapy: Radiation
  • Hypertension: Hypercholesterolemia: Glycosuria: Polyphagia


VII. Answer in a sentence


2> Mention the diseases caused by tobacco smoke.

Ans:The diseases caused by tobacco smoke are pulmonary tuberculosis, emphysema hypoxia, lung cancer, hypertension gastric and duodenal ulcer, bronchitis etc.


3> What are the contributing factors for Obesity?

Ans: The contributing factors for obesity are as given below:

  • Genetic factors
  • Physical inactivity
  • Overheating
  • Endocrine factors


4> What is adult onset diabetes?

Ans:Type-2 Non-Insulin Dependent Diabetes Mellitus i.e. NIDDM is called as adult onset diabetes.


5> What is metastasis?

Ans: The cancerous cells migrates to distant parts of the body and thereby affect the new tissues, this process is called metastasis.


6> How does insulin deficiency occur?

Ans:The insulin deficiency occurs due to the destruction of beta cells of the pancreas, which is characterized by abnormally increased blood glucose levels which results from the inadequate insulin secretion.


 VIII. Short answer questions


1> What are the various routes by which transmission of human immuno deficiency virus takes place?


  • The various routes by which transmission of human immunodeficiency virus takes place are as follows:
  • Due to the sexual contact with infected person.
  • Due to the use of contaminated needles or syringes, especially in case of intravenous drug abusers.
  • Due to the transfusion of contaminated or infected blood or blood products.
  • It will be also transmitted from mother to her child through placenta.


2> How is a cancer cell different from a normal cell?


The abnormal and uncontrolled division of cells which invade and destroy surrounding tissue which forms the tumor or neoplasm is known as cancer. Cancer tumor is the heterogeneous group of cells which do not respond to normal cell division.

The cancerous cells affects the new tissues by migrating to doistant parts of the body such as lungs, liver, bones, skin and brain. This is the process called as metastasis.


3> Differentiate between Type-1 and Type-2 diabetes mellitus


Type-1 diabetes mellitus:

  • The patients with type-2 diabetes mellitus do not produce insulin in the pancreas.
  • It causes at the juvenile onset i.e. below the age about 20 years.
  • In this, the immune system destroys the insulin producing beta cells in pancreas.
  • Type-1 diabetes mellitus cannot be controlled without taking insulin.

Type-2 diabetes mellitus:

  • The patients with type-2 diabetes mellitus do not respond to insulin.
  • It may causes at maturity onset i.e. above the age of 30 years.
  • This patients are insulin resistant that means insulin is produced in the body but it cannot be used effectively.
  • Type-2 diabetes mellitus can be treated initially without medication or by taking tablets also.


4> Why is a dietary restriction recommended for an obese individual?


  • Obesity is the state in which there is an accumulation of extra body fat due to which there is abnormal increase in body weight.
  • Obesity occurs due to the excess intake of calories than the expenditure of energy.
  • Dietary restrictions recommend for an obese individual because of following causes and Risk factors:
  • Obesity is a positive risk factor in developing hypertension, diabetes, gall bladder diseases, coronary heart disease and arthritis.
  • Obesity causes due to genetic factors, physical inactivity, overheating and endocrine factors.
  • To avoid all these risk factors dietary restrictions are recommended for obese individual.


5> What precautions can be taken for preventing heart diseases?

Ans: The precautions and controls of heart disease are as follows:

Diet management:

  • Some dietary modifications needed are reducing intake of calories, low saturated fat and cholesterol rich food, low carbohydrate and common salts etc.
  • The diet must be rich in polyunsaturated fatty acids is necessary.
  • We have to increase the intake of fibre diet, fruits and vegetables, proteins, minerals and vitamins are mostly required.
  • Physical activities included are regular exercise, walking and yoga are must necessary for body weight management.
  • The addictive substances such as alcohol consumption and smoking must be avoided.


Long answer questions


1> Suggest measures to overcome the problems of an alcoholic.

Ans: The measures suggested to overcome the problems of an alcoholic are as follows:

  • 1.) Education and counseling:

·         To overcome the problems and stress and also to accept failures in the life of alcoholic person education and proper counseling is most helpful.

  • 2.) Physical activity:

·         Alcoholic persons have to change their habits and start with new habits like reading, music, sports, yoga and meditation which makes them apart from their stress in life and stay them happy.

  • 3.) Seeking help from parents and peer groups:

·         When some problematic situations occurs in the life of affected person they need the advice and guidance of parents and peer groups. This would help them to share their feelings freely, avoid them to do wrong things and get rid of the habit.

  • 4.) Medical assistance:

·         They need also the help from psychologist and also from psychiatrist to get free from all these conditions and to live a healthy, happy and peaceful life. Alcohol de-addiction and rehabilitation programs should have to attend by that affected person so that they get out of all problems and live a healthy normal life.


2>  Changes in lifestyle is a risk factor for occurrence of cardiovascular diseases. Can it be modified? If yes, suggest measures for prevention.

Ans: The lifestyle can also be modified in order to prevent cardiovascular disease. Some measures are suggested for prevention which are as follows:

  • Do daily exercise.
  •  Only eat a heart-healthy diet.
  • Don’t smoke and avoid use of tobacco.
  • Maintain the weight according to height.
  • Keep calm and manage stress by taking a enough sleep.
  • Cholesterol will be in control.
  • Increase the food in diet like fruits, vegetables, proteins, vitamins and  minerals which are necessary.
  • ·Diet must be rich with polyunsaturated fatty acids.
  • Reduce intake of calories, low saturated fat and cholesterol rich food, low carbohydrate and common salts are the some dietary modifications.


X. Higher Order Thinking Skills (HOTS)


1> What is the role of fat in the cause of atherosclerosis?

Ans: The role of fat in causing atherosclerosis is as follows:

It is caused due to the deposition of cholesterol in the blood vessels. It may develops slowly over many years from childhood. It forms the fatty streak to a fibrous complicated plaque, which results in narrowing blood vessels and causes atherosclerosis in the large and medium sized arteries which supplies heart muscle with oxygen. Then it leads to ischemia and myocardial infarction.


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?

Ans: Suggestions for children to avoid eating junk food and consumption of soft drinks are as follows:

  • When we go outside then don’t drink soft drinks, always carry a water bottle and drink water.
  • When children are feeling tired give them fruit juices, energy drinks to get energy not the soft drinks.
  • In daily diet incudes the food which gives more energy, proteins and minerals.
  • Give them nuts, dry fruits, different types of legumes and fruits when they feel hungry and avoid junk food.
  • Don’t wait for the getting extremely hungry due to which children can’t eat properly and get tired early.
  • Try to teach them yoga and meditation to maintain peaceful mind.
  • Children must have enough sleep so they get free from stress.
  • In this way we can avoid children from taking the junk food and consumption of soft drinks.


3> Regular physical exercise is advisable for normal functioning of human body.   What are the advantages of practicing exercise in daily life?


  • Regular physical exercise is advisable for normal functioning of human body.
  • Because, physical exercise make our mind relaxed and peaceful due to which we become mentally stable.
  • It help us to have long life and also prevent us from many chronic diseases.
  • Daily physical exercise makes us strong, healthy and increases our immunity also and hence we become hungrier in order to get more energy.
  • This leads to maintain our body healthy.
  • It also reduces stress, anxiety and depression and make our mind healthy.
  • It will increases sleep to maintain human body health.
  • Also it maintain body weight due to which the most of the diseases get avoided.
  • The healthy regular diet, daily exercise and enough sleep is the key to become mentally and physically healthy.


4>  A leading weekly magazine has recently published a survey analysis which says that 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 you face when trying to educate the people in your village near by your school?

  • Most of the AIDS patients feel ashamed telling their problems, they don’t want to share their thoughts with others because of the people bad behaviour or thinking about them.
  • They wish to live alone and makes distance from family.
  • They are mainly suffering from afraid of AIDS and people’s thinking towards them due to which they are in depression about their future.
  • They are not interested in any type of consultant and can’t accept any news.

b) How do you overcome the problem?

  • Firstly they have to confirm the disease by taking proper test.
  • If they are suffering from AIDS then we have to support them not to publish their problems in front of others.
  • We have to be always there for their any need.
  • We have to play and enjoy with them by doing short tour or walk in order to reduce their mental stress.
  • We have to prevent them from bad activities which spread the disease and advise them to take care of ourselves.
  • We have to aware them by educating them about HIV and AIDS and thereby we should not be isolate them from their families.


XI. Value based questions


2. Men addicted to tobacco lead to oxygen deficiency in their body. What could be the possible reason?

Ans: Because, addiction of tobacco due to nicotine, an alkaloid present in it, which is highly harmful and poisonous substance. The carbon dioxide of tobacco smoke get binded with haemoglobin of RBCs and due to which its oxygen carrying capacity decreases and causes hypoxia in the body tissues.


3. Name any three foods that are to be avoided and included in the diet of a diabetic patient. Why should it be followed?


  • Refined sugar, carbohydrate rich food and food rich in high fat also be avoided.
  • Diet comprising whole grains, millets like jowar, bajra, ragi, green leafy vegetables, wheat and unpolished rice should be included regularly in daily diet.
  • Avoiding and including foods like these maintain the blood sugar level and keep human body as healthy.


4>  How can informational efforts change people’s HIV knowledge and behaviour ?


  • We have to find the detail information of HIV and AIDS that means how it can be prevented, controlled, and reduced.
  • We have learn firstly how to behave with person suffering from AIDS in order to make them stress free.
  • We have to keep their mental health normal and have to help them which needs they are.
  • We have to give them proper treatment at proper time.


XII. Assertion and Reasoning 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 and Reason are true that Reason is not the correct explanation of Asssertion

c. Assertion is true but Reason is false

d. Both Assertion and Reason are false

1. Assertion: All drugs act on the brain.

Reason: Drugs disturb the functioning of the body and mind.

Ans: a. if both Assertion and Reason are true and Reason is the correct explanation of Assertion

2.Assertion: Excretion of excess glucose in urine is observed in a person with diabetes mellitus.

Reason: Pancreas is unable to produce sufficient quantity of insulin.

Ans: b. if both Assertion and Reason are true that Reason is not the correct explanation of Assertion.



Here is your solution of Samacheer Kalvi 10th Science Chapter 21 

Dear Student, I appreciate your efforts and hard work that you all had put in. Thank you for being concerned with us and I wish you for your continued success. 

Updated: June 26, 2021 — 3:26 pm

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