Exercise Solutions Available
Step-by-step answers for all textbook questions in this chapter
Health and Hygiene — Exercise Solutions
Use this guide alongside the Samacheer Kalvi textbook. Solve every question on your own first, then check below.
I. Choose the Appropriate Answer (MCQs)
Q1. Our body needs \_\_\_\_\_\_ for muscle-building. (a) Carbohydrate (b) Fat (c) Protein (d) Water
Proteins are body-building nutrients. They repair worn-out tissues and help build new ones, making them essential for muscle growth.
Q2. Scurvy is caused due to the deficiency of \_\_\_\_\_\_. (a) Vitamin A (b) Vitamin B (c) Vitamin C (d) Vitamin D
Vitamin C is needed for collagen synthesis and wound healing. Its deficiency causes scurvy — symptoms include bleeding gums, loose teeth, and delayed wound healing.
Q3. Calcium is an example of a \_\_\_\_\_\_. (a) Carbohydrate (b) Fat (c) Protein (d) Minerals
Calcium is a mineral, not an energy-giving or body-building nutrient. It strengthens bones and teeth, and helps in blood clotting.
Q4. We should include fruits and vegetables in our diet, because \_\_\_\_\_\_. (a) Best source of Carbohydrates (b) Best source of Proteins (c) Rich in minerals and vitamins (d) High water content
Fruits and vegetables are called protective foods because they are packed with vitamins and minerals that protect the body from diseases.
Q5. Bacteria are very small \_\_\_\_\_\_ microorganism. (a) Prokaryotic (b) Eukaryotic (c) Protozoa (d) Acellular
Bacteria lack a true nucleus and membrane-bound organelles, which makes them prokaryotic organisms.
II. True or False (with corrections)
Q1. There are three main nutrients present in food.
Correction: There are six main nutrients in food — carbohydrates, proteins, fats, vitamins, minerals, and water.
Q2. Fats are used as an energy store by our body.
Fats provide more than twice the energy per gram compared to carbohydrates and are stored in adipose tissue for later use.
Q3. All bacteria have flagella.
Correction: Only some bacteria have flagella. Flagella are present only in bacteria that need to move; many bacteria are non-motile.
Q4. Iron helps in the formation of haemoglobin.
Iron is a key component of haemoglobin, the pigment in red blood cells that carries oxygen throughout the body.
Q5. Virus can grow and multiply outside host.
Correction: Viruses are obligate intracellular parasites — they can grow and multiply only inside a living host cell.
III. Fill in the Blanks
1. Malnutrition leads to deficiency disease.
2. Iodine deficiency leads to goitre in adults.
3. Vitamin D deficiency causes Rickets.
4. Typhoid is transmitted due to contamination of food and water.
5. Influenza is a viral disease.
IV. Complete the Analogy
1. Rice : Carbohydrate :: Pulses : Protein
Pulses are a rich source of protein, just as rice is a rich source of carbohydrates.
2. Vitamin D : Rickets :: Vitamin C : Scurvy
Just as Vitamin D deficiency causes Rickets, Vitamin C deficiency causes Scurvy.
3. Iodine : Goitre :: Iron : Anaemia
Just as iodine deficiency causes goitre, iron deficiency causes anaemia.
4. Cholera : Bacteria :: Smallpox : Virus
Just as cholera is caused by bacteria, smallpox is caused by a virus.
V. Match the Following
| Vitamin | Deficiency Disease |
|---|---|
| Vitamin A | Night blindness |
| Vitamin B1 | Beri beri |
| Vitamin C | Scurvy |
| Vitamin D | Rickets |
| Vitamin E | Sterility |
VI. Short Answer Questions
Q1. Write two examples for each of the following: (a) Foods rich in fat (b) Foods rich in protein
- (a) Foods rich in fat: Egg yolk, Meat
- (b) Foods rich in protein: Soya beans, Grams (lentils)
Q2. Differentiate between carbohydrates and protein.
| Feature | Carbohydrates | Proteins |
|---|---|---|
| Function | Energy-giving nutrients | Body-building nutrients |
| Role | Provide fuel for daily activities | Growth and repair of tissues |
| Examples | Rice, wheat, sugar, starch | Soya beans, grams, meat, eggs |
| Requirement | Needed in large quantities | Needed in moderate quantities |
Q3. Define 'balanced diet'.
A balanced diet is a diet that contains adequate amounts of all essential nutrients — carbohydrates, fats, proteins, vitamins, minerals, fibre, and water — in proper proportions, required for healthy growth, development, and activity of the body.
Q4. Why should fruits and vegetables not be washed after cutting?
Water-soluble vitamins (especially Vitamin B and Vitamin C) get dissolved and washed away when fruits and vegetables are washed after cutting. Cutting should be done first, followed by minimal washing.
Q5. Write any two viral diseases.
Q6. What is the main feature of a microorganism?
- Microbes can only be seen through a microscope.
- Bacteria are prokaryotic — they lack a true nucleus.
- Bacteria can live independently or as parasites.
- Viruses are acellular organisms — they have no cell structure.
- Viruses can live and reproduce only inside a living host organism.
VII. Detailed Answer Questions
Q1. Tabulate the vitamins and their corresponding deficiency diseases.
| Vitamin | Deficiency Disease |
|---|---|
| Vitamin A | Night blindness |
| Vitamin B1 | Beri beri |
| Vitamin B2 | Ariboflavinosis |
| Vitamin B6 | Dermatitis |
| Vitamin B12 | Pernicious anaemia |
| Vitamin C | Scurvy |
| Vitamin D | Rickets |
| Vitamin E | Sterility / Nervous weakness |
| Vitamin K | Bleeding (delayed clotting) |
Q2. Explain the role of minerals in the human body with deficiency diseases.
Minerals regulate normal body functions. Key minerals and their deficiency diseases:
| Mineral | Function | Deficiency Disease |
|---|---|---|
| Calcium | Strong bones, teeth, blood clotting | Rickets (children), Osteomalacia (adults) |
| Phosphorus | Bone and teeth formation | Osteomalacia |
| Iron | Haemoglobin formation | Anaemia |
| Iodine | Thyroid hormone synthesis | Goitre (adults), Cretinism (children) |
Q3. How does a balanced diet help our body?
A balanced diet helps the body in four important ways: 1. Increased capacity to work — adequate nutrients fuel physical and mental activities. 2. Good physical and mental health — proper nourishment keeps the body and mind in good condition. 3. Increased capacity to resist diseases — vitamins and minerals boost immunity. 4. Proper growth of the body — proteins and minerals support growth and development.
Q4. Describe the transmission of bacterial diseases.
| Disease | Mode of Transmission |
|---|---|
| Cholera | Contaminated water and food |
| Tetanus | Wound contamination with bacteria |
| Typhoid | Contaminated food and water |
| Tuberculosis | Air (droplet infection — coughing, sneezing) |
Bacterial diseases spread through contaminated food, water, air, and direct contact with infected persons or contaminated wounds.
Q5. Define health and disease. How are they related?
Health is a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.
Disease is a definite pathological process having a characteristic set of signs and symptoms that affects the normal functioning of the body.
Relationship: Health and disease are opposites. When the body is in a state of well-being, it is healthy. When the body's normal functions are disturbed by pathogens, deficiency, or other factors, disease occurs. Good hygiene, nutrition, and exercise maintain health and prevent disease.
Q6. What is a retrovirus? Give an example.
A retrovirus is a virus that contains RNA instead of DNA as its genetic material. It uses an enzyme called reverse transcriptase to convert its RNA into DNA inside the host cell. Example: HIV (Human Immunodeficiency Virus), which causes AIDS.
Additional Practice Questions
MCQs
Q1. \_\_\_\_\_\_ provides more energy than Carbohydrates. (a) Fat (b) Vitamin (c) Protein (d) Water
Fat provides approximately 9 kcal/g, while carbohydrates provide about 4 kcal/g.
Q2. Vitamin rich in Gooseberry: (a) C (b) E (c) B (d) D
Gooseberry (amla) is particularly rich in Vitamin B complex along with Vitamin C.
Q3. Water-soluble vitamin among the options: (a) Vitamin A (b) Vitamin B (c) Vitamin D (d) Vitamin E
Vitamin B and Vitamin C are water-soluble; Vitamins A, D, E, and K are fat-soluble.
Q4. Vitamin present in Moringa leaves: (a) A and B (b) C and D (c) K and A (d) A and C
Moringa leaves are rich in Vitamin A and Vitamin C, along with minerals like potassium, calcium, and iron.
Q5. \_\_\_\_\_\_ is made in our skin using sunlight. (a) Vitamin D (b) Vitamin C (c) Vitamin A (d) Vitamin B
When ultraviolet (UV) rays from sunlight hit the skin, they trigger Vitamin D synthesis. Sunscreen lotion can reduce this by up to 95%.
Q6. \_\_\_\_\_\_ are required for growth and regulation of normal body function. (a) Fats (b) Proteins (c) Carbohydrates (d) Minerals
Minerals play a crucial role in regulating body functions and supporting growth.
Q7. 80% of world Moringa production is in: (a) China (b) Germany (c) India (d) Canada
India is the largest producer of Moringa, contributing about 80% of global production.
Q8. Minimum daily water intake: (a) 2 litres (b) 3 litres (c) 8 litres (d) 6 litres
A minimum of 2 litres of water per day is recommended for proper body function.
Q9. Bacterial disease transmitted through wound contamination: (a) Cholera (b) Tetanus (c) Typhoid (d) Pneumonia
Tetanus bacteria (Clostridium tetani) enter the body through wounds or cuts.
Q10. Acellular agent replicating only inside living cells: (a) Bacteria (b) Protozoa (c) Fungi (d) Virus
Viruses are acellular (no cell structure) and can replicate only inside a living host cell.
Fill in the Blanks (Additional)
1. We obtain Carbohydrates as Sugar, Starch, and Dietary Fibres. 2. Vitamins are called Protective foods. 3. Vitamins A, D, E, K are fat-soluble vitamins. 4. Vitamin E deficiency disease: Nervous Weakness. 5. Moringa leaves contain powerful anti-Oxidants. 6. Skinny appearance and slow growth are symptoms of Marasmus. 7. Physical exercise strengthens muscles and the cardiovascular system. 8. Viruses can kill, damage, or change cells and make you sick. 9. Sunscreen lotion reduces the skin's ability to produce Vitamin D by up to 95%. 10. Gooseberries contain nearly 20 times more vitamin C than an orange. 11. India has the second highest number of obese children in the world.
True or False (Additional)
Q1. Minerals carry out various biochemical reactions in our body.
Q2. Night blindness is caused by Vitamin A deficiency.
Q3. Vitamin D is abundantly found in orange and gooseberry.
Q4. Sunscreen lotion reduces the ability to produce Vitamin D, leading to deficiency diseases.
Sunscreen can reduce Vitamin D production by up to 95%.
Q5. Iodine maintains strong bones, teeth and helps in clotting of blood.
Q6. Moringa leaves are rich in potassium, calcium and iron.
Complete the Analogy (Additional)
1. Polio : Virus :: Tetanus : Bacteria 2. Kwashiorkor : Diarrhoea :: Marasmus : Slow body growth 3. Synthesis of thyroid hormone : Iodine :: Formation of haemoglobin : Iron 4. Fish oil : Vitamin D :: Vegetable oil : Vitamin E 5. Vitamin K : Clotting of blood :: Vitamin E : Fertility 6. Protein : Soya bean :: Fat : Meat
Match the Following (Additional)
1. Carbohydrate — (c) Energy-giving component 2. Proteins — (d) Body-building food 3. Vitamins — (a) Carrying out various biochemical reactions 4. Minerals — (b) Regulation of normal body function
Short Answers (Additional)
Q1. Define homeostasis.
Q2. List the nutrients obtained from food.
Q3. Define deficiency diseases.
Q4. Sunscreen lotion is not good for health — justify.
Q5. Nutrients in Moringa leaves.
Q6. What are the four major groups of microbes?
Q7. Define disease.
Intext Activities
Activity 3 — Starch Test: When iodine solution is added to a potato slice, it turns blue-black. This confirms the presence of starch (a carbohydrate) in the potato.
Activity 4 — Fat Test: When a drop of oil is placed on paper and held against light, the paper appears translucent and greasy. This confirms the presence of fat.
Activity 5 — Protein Test: When egg white is mixed with CuSO₄ and NaOH, it turns purple/violet. This confirms the presence of protein.
Activity 6 — Sprouting: Green gram sprouts provide fibre, Vitamin B, Vitamin C, and Vitamin K, making sprouts a nutritious food.
Activity 7 — Balanced Diet Chart (12-year-old): A balanced diet chart includes idli/rice (carbohydrate), dal/grams (protein), vegetables and fruits (vitamins and minerals), milk (calcium and protein), and fats in proper proportions across all meals.
Activity 9 — ORS Preparation: Ingredients: 1 litre of boiled and cooled water + ½ teaspoon of salt + 6 teaspoons of sugar + a few drops of lemon juice. ORS helps restore water and electrolyte balance during dehydration.
Discussion — Is virus living or non-living?
- It is acellular (has no cell structure).
- It is an obligate parasite — cannot survive or reproduce outside a host.
- It lacks its own energy-generating system.
- It cannot perform metabolic activities on its own.
- It does not reproduce from pre-existing viruses — it replicates by taking over the host cell's machinery.
Common Mistakes
1. Confusing "three nutrients" with "six nutrients" — There are SIX main nutrients: carbohydrates, proteins, fats, vitamins, minerals, and water. Exam questions often test this.
2. Mixing up fat-soluble and water-soluble vitamins — Vitamins A, D, E, K are fat-soluble; Vitamins B and C are water-soluble. Washing cut vegetables loses water-soluble vitamins.
3. Saying "all bacteria have flagella" — Only motile bacteria possess flagella. Many bacteria are non-motile.
4. Confusing Calcium with Iodine — Calcium is for bones, teeth, and blood clotting. Iodine is for thyroid hormone synthesis. Do not mix up their deficiency diseases.
5. Saying viruses can grow outside a host — Viruses are obligate intracellular parasites. They replicate ONLY inside a living host cell.
6. Confusing Vitamin C and Vitamin D sources — Oranges and gooseberries are rich in Vitamin C (not D). Sunlight helps produce Vitamin D in the skin.
7. Mixing up Kwashiorkor and Marasmus — Kwashiorkor is protein deficiency (swollen belly, oedema). Marasmus is overall calorie deficiency (skinny appearance, slow growth).
Exam Checklist
- [ ] Can list all six nutrients and their functions
- [ ] Can match each vitamin (A, B1, C, D, E, K) with its deficiency disease
- [ ] Can match each mineral (Calcium, Phosphorus, Iron, Iodine) with its deficiency disease
- [ ] Can define health, disease, balanced diet, and homeostasis
- [ ] Can differentiate carbohydrates, proteins, and fats with examples
- [ ] Know the four groups of microbes (Bacteria, Virus, Protozoa, Fungi)
- [ ] Can name at least two bacterial diseases and their transmission modes
- [ ] Can name at least two viral diseases
- [ ] Understand why fruits/vegetables should not be washed after cutting
- [ ] Know the effect of sunscreen on Vitamin D synthesis
- [ ] Can explain why virus is considered non-living
- [ ] Can prepare ORS and state its purpose
- [ ] Can complete analogies involving nutrients and deficiency diseases