0654_2017_O/N_QP_22_Biology

1.What is homeostasis?

• the maintenance of the body’s external environment

• the maintenance of the body’s internal environment

• the processes that produce heat in the body

• the removal of wastes from the body

2.What is excretion?

• breakdown of materials in kidney cells

• chemical reactions in liver cells

• removal of undigested food from the gut

• removal of waste products

3.What would increase the risk of coronary heart disease?

• reduced salt diet

• relaxation therapy

• regular exercise

• smoking tobacco

4.Which statements about X chromosomes in humans are correct?

• A

• B

• C

• D

5.The test-tube shows gelatine with a layer of black dye. The dye can diffuse through the gelatine.

What was the appearance of the test-tube after six hours?

• 
• 
• 
• 

6.Which component of cigarette smoke can bind to haemoglobin and reduce the ability of the blood

to carry oxygen?

• carbon monoxide

• nicotine

• smoke particles

• tar

7.When a suspension of powdered milk is completely digested by a protease enzyme it becomes

clear.

The graph shows the time taken for a mixture of protease and powdered milk to clear at different

temperatures.

What is this enzyme’s optimum temperature?

• 5 °C

• 37 °C

• 40 °C

• 50 °C

8.What is a function of bile?

• emulsifying carbohydrates to decrease the surface area for the action of enzymes

• emulsifying carbohydrates to increase the surface area for the action of enzymes

• emulsifying fats to decrease the surface area for the action of enzymes

• emulsifying fats to increase the surface area for the action of enzymes

9.Predators that hunt at night have large eyes and ears.

This has resulted from the passing on of genes by the best-adapted organisms.

What is this process called?

• artificial selection

• conservation

• homeostasis

• natural selection

10.Why might auxins be used in the commercial growth of plants?

• to increase uptake of carbon dioxide for increased photosynthesis

• to reduce the amount of water needed by the plants

• to regulate growth of particular parts of the plants

• to stimulate production of chlorophyll for increased yield