CBSE Class 4 Science Food and digestion

I DEFINE – KEY TERMS (PAGE 22)

II ANSWER THE FOLLOWING QUESTIONS.

1. Why do we need food?

Ans. We need food –

a. To give us energy.

b. To protect us from diseases.

c. To build and repair parts of our body.

d. For growth.

2. Why are children asked to eat protein rich food?

Ans. Protein helps to repair and build different parts of our body. Hence, children are asked to eat lots of protein rich food.

3. What is a balanced diet?

Ans. The diet which contains all the types of nutrients in right amount is called balanced diet.

4. What are the advantages of cooked food?

Ans. Cooking makes the food soft, easy to chew and tasty. Cooking also makes the food easy to digest and kills the germs present in it.

5. Name three substances that can be added to food to preserve it.

Ans. Sugar syrup, salt or vinegar can be added to preserve food.

6. Name three organs of your digestive system which make digestive juices.

Ans. Mouth, stomach and small intestine are the organs in the digestive system which makes digestive juices.

7. How is saliva useful in digestive food?

Ans. Saliva present in mouth helps –

a. To make the food soft.

b. To break down starch to sugar.

8. How are some microbes useful to us?

Ans. i. some bacteria help to prepare curd, wine and vinegar.

ii. Some fungi like yeast are used to prepare bread, idlis, cakes etc.