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Each different valid point you make is worth 0.5 mark.
Write your answers as sentences.
Use the essence of the question as the start of your answer.

1. List four ways in which the surface area of the small intestine is increased for greater absorption of nutrients. (2 marks)

2. Explain the need for the small intestine to have a rich supply of blood vessels. (1 mark)

3. Which small organic food molecules are absorbed into the capillaries and which are absorbed into the lacteals? (2 marks)

4. Absorption of nutrients occurs by the process of diffusion and active transport. Distinguish between these processes. (2 marks)

5. What is the name of the blood vessel which carries absorbed nutrients from the small intestine to the liver? (1 mark)

6. Why are food molecules taken to the liver before they go anywhere else in the body? (1 mark)

7. What eventually happens to the fats which are absorbed into the lacteals of the villi? (1 mark)

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Give the most suitable human biology term for each of the following.

1. Rhythmic, successive, wavelike contractions moving along the walls of the alimentary canal that causes the passage of materials within.

2. Liquid form of food within the stomach and small intestine.

3. The common area at the back of the mouth and nose through which both food and air pass.

4. A muscle arranged in a circular manner around a tube or opening. It behaves like a drawstring in controlling the size of the opening.

5. The process of causing dietary fats to be suspended in very small droplets in the watery medium of the small intestine, thereby increasing the surface area of the fats available to enzymes.

6. The transfer of digested nutrients from the small intestine to the blood and lymph.

7. The process of chewing.

8. A cavity within a tube or cell, e.g. the cavity within the digestive tract through which the food passes.

9. The process of removing undigested material from the large intestine through the anus.

10. A chemical process which goes on inside all living cells causing the release of energy from food.

11. A substance produced by the liver and stored in the gall bladder. It contains salts which are necessary for the breakdown of fats.

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