Health and Hygiene — Class 6 Science (Samacheer Kalvi)
TN State Board (Samacheer Kalvi) Class 6 Science, Term 1 — Chapter 6. Nutrients, a balanced diet and good health.
1. About this chapter
This chapter covers the nutrients in food, deficiency diseases, the balanced diet, and disease-causing microorganisms.
2. Nutrients in food
- Food has six main nutrients: carbohydrates, fats, proteins, vitamins, minerals and water.
- Carbohydrates (rice, bread) give energy; fats (oil, ghee) are an energy store; proteins (pulses, egg, milk) are for growth and muscle-building.
- Vitamins and minerals (in fruits and vegetables) protect the body in small amounts. (Analogy: rice : carbohydrate :: pulses : protein.)
3. Deficiency diseases
| Deficiency | Disease |
|---|---|
| Vitamin C | scurvy |
| Vitamin D | rickets |
| Iodine (a mineral) | goitre |
| Iron (a mineral) | anaemia |
- Iron helps form haemoglobin in the blood; calcium (for bones and teeth) is a mineral.
4. Balanced diet and microorganisms
- A balanced diet contains an adequate amount of all the nutrients (carbohydrate, fat, protein, vitamins, minerals and water) for healthy growth and activity.
- Bacteria are very small prokaryotic microorganisms; only some bacteria have flagella. Viruses can grow and multiply only inside a host. (Cholera is caused by bacteria; smallpox by a virus.)
5. Worked examples
Example 1. Which vitamin deficiency causes scurvy? Vitamin C.
Example 2. Which nutrient builds muscles? Protein.
Example 3. Where can a virus grow and multiply? Only inside a host.
6. Book-back questions (Samacheer Kalvi)
I. Choose the correct answer
- Our body needs ____ for muscle-building — (a) carbohydrate / (b) protein. Ans: (b) protein.
- Scurvy is caused by the deficiency of — (a) vitamin C / (b) iron. Ans: (a) vitamin C.
- Calcium is an example of a — (a) vitamin / (b) mineral. Ans: (b) mineral.
II. Analogy (fill in) 4. Rice : carbohydrate :: pulses : protein. 5. Vitamin D : rickets :: vitamin C : scurvy. 6. Iodine : goitre :: iron : anaemia. 7. Cholera : bacteria :: smallpox : virus.
III. True or False 8. There are three main nutrients present in food. — False (there are six). 9. Fats are used as an energy store by our body. — True. 10. All bacteria have flagella. — False (only some do). 11. A virus can grow and multiply outside a host. — False (only inside a host).
7. Common mistakes
- Mistake: Saying there are three nutrients. Fix: There are six nutrients (carbohydrates, fats, proteins, vitamins, minerals, water).
- Mistake: Calling vitamin-D deficiency scurvy. Fix: Vitamin C → scurvy; vitamin D → rickets.
- Mistake: Thinking viruses multiply on their own. Fix: Viruses multiply only inside a host.
8. Quick revision
- Term 1 · Ch 6 · health and hygiene.
- Six nutrients: carbohydrate (energy), fat (energy store), protein (growth), vitamins, minerals, water.
- Deficiency: vitamin C → scurvy, vitamin D → rickets, iodine → goitre, iron → anaemia (iron makes haemoglobin); calcium = mineral.
- Balanced diet = all nutrients in right amounts; bacteria = prokaryotic (some have flagella); virus multiplies only inside a host.
