Explain the process of nutrition in Amoeba.

Mention the major events during photosynthesis.

Explain the process of digestion of food in mouth, stomach and small intestine in human body.

How are fats digested in our bodies? Where does this process take place?

There are five animals P, Q, R, S and T. The animal P always lives in water and has gills for breathing. The animal Q can stay in water as well as on land and can breathe both, through moist skin and lungs. The animal R lives in soil and breathes only through its skin. The animal S lives on land and breathes through spiracles and tracheae. And animal T lives in water and breathes through its cell membrane.

1. Which of the animals could be Amoeba?
2. Which of the animals could be frog?
3. Which animal could be fish?
4. Which animal could be grasshopper?
5. Which animal could be earthworm?

Explain the process of breathing in man.

Describe the exchange of gases which takes place in the leaves of a plant:

1. During daytime.
2. At night.

Excretion is different in multi-cellular organisms as compared to unicellular organisms. How?

A liquid X of colour Y circulates in the human body only in one direction: from body tissues to the heart. Among other things, liquid X contains germs from cells and dead cells. The liquid X is cleaned of germs and dead cells by a special type of white blood cells called Z. This cleaned liquid is then put into blood circulatory system in subclavian veins.

1. What is (i) liquid X and (ii) colour Y?
2. What are Z.
3. The liquid X is somewhat similar to a component of blood. Name this component.
4. Why is liquid X not red?

1. Draw a diagram of human alimentary canal and label on it: Oesophagus, Gallbladder, Liver and Pancreas.
2. Explain the statement, ‘Bile does not contain any enzyme but it is essential for digestion.’