Water and dissolved minerals get into the root hair of a plant by a process called A and enter the conducting tissue B. The process C helps the water and dissolved minerals to move up through the tissue B in roots and stem, and reach the leaves of a plant. In the leaves food is made by a process D. This food is then transported to all the parts of a plant through tissue E. The process of distributing food made in the leaves to all the parts of the plants is called F.

1. What are (i) A, (ii) B, (iii) C, (iv) D, (v) E, and (vi) F?
2. Which tissue is made up of living cells: B or E?
3. Which tissue, B or E, contains sieve tubes?
4. Which tissue, B or E, contains tracheids?

1. Why is there a difference in the rate of breathing between aquatic organisms and terrestrial organisms? Explain.
2. Draw a diagram of human respiratory system and label-pharynx, trachea, lungs, diaphragm and alveolar sac on it.

The process of ultra-filtration is essential in urine formation, where does this step occur in nephron?

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

1. During daytime.
2. At night.

If the teeth are not cleaned regularly, they become covered with a sticky yellowish layer W of food particles and bacteria. Since layer W covers the teeth, the alkaline liquid X secreted by glands Y inside the mouth cannot reach the teeth surface to neutralise the acid formed by the action of organisms Z on sugary food, and hence tooth decay sets in.

1. What is W known as?
2. What is (i) X, and (ii) Y?
3. What are organisms Z?
4. State one way of removing layer W from the teeth.

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

Distinguish between photosynthesis and respiration.

Second stage of urine formation is called selective re-absorption. Why?

1. Draw a diagram of human alimentary canal and label - gall bladder, pancreas, liver and small intestine on it.
2. Give two reasons to explain why absorption of digested food occurs mainly in the small intestine.

An organism X having breathing organs A lives on land. When organism X goes under water, it cannot survive for a long time unless carrying an oxygen cylinder. On the other hand, the organism Y having breathing organs B always lives in water and if taken out of water, it dies after a short while. A third organism Z having breathing organs C and D which lives on the banks of ponds, lakes and rivers can survive on land as well as in water equally well.

1. What could organism X be? Name the breathing organs A.
2. What could organism Y be? Name the breathing organs B.
3. What could organism Z be? Name the breathing organs C and D.
4. Out of X, Y and Z, which organism is.

1. Amphibian,
2. Aquatic,
3. Terrestrial?