Q57 of 79 Page 54

Mention the major events during photosynthesis.

The process of photosynthesis takes place in the following three steps:

• Absorption of light energy by chlorophyll

• Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen.

• Reduction of carbon dioxide to carbohydrates.

Why is blood circulation in human heart called double circulation?

What is the advantage of having four chambered heart?

In each of the following situations what happens to the rate of photosynthesis?

(i) Cloudy days

(ii) No rainfall in the area

(iii) Good manuring in the area

(iv) Stomata get blocked due to dust

(v) What causes movement of food inside the alimentary canal?

Name the energy currency in the living organisms. When and where is it produced?