9th Grade Science DST 2
Tuesday 17th October 2023
Unit 2, Animal Physiology, Topic 2: The variety of living organisms
1. The diagram shows a species of protoctist called Euglena. Use the diagram to
explain why Euglena is classified as a protoctist and not as an animal or plant. (2
marks)
2. Define the term invertebrate (1 mark)
Unit 2, Animal Physiology, Topic 3: Breathing and Gas Exchange
3. What is the difference between respiration and breathing? (1 mark)
4. Name three disease associated with smoking (3 marks)
5. What name is given to the drug found in smoking? (1 mark)
6. Chemicals in cigarette smoke lead to the breakdown of the walls of the alveoli.
What is the name given to this disease? (1 mark)
A
B
C
D
bronchitis
emphysema
coronary heart disease
lung cancer
7. Explain the effects of smoking on the circulatory system (3 marks)
8. The diagram below shows the structure of the thorax. What is the function
of the intercostal muscles? (1 mark)
9. In which of the following structures does gas exchange occur (1 mark)
A
B
C
D
alveolus
bronchiole
bronchus
trachea
10. Suggest three ways the alveoli are adapted for efficient gas exchange (3
marks)
11. Explain the differences between the lung diseases bronchitis and emphysema?
(3 marks)
Unit 2, Animal Physiology, Topic 4: Food and Digestion
12. Define the term digestion. (1 mark)
13. Name three organs of the digestion system (3 marks)
14. Name three accessory organs of digestion (3 marks)
15. Which of following statements about digestion is not correct (1 mark)
A
B
C
D
Digestion produces fatty acids and glycerol
Digestion converts insoluble molecules into soluble molecules
Digestion changes proteins into amino acids
Digestion releases energy from food
16. Name two enzymes that digest food. (1 mark)
17. Explain how enzymes are used in the digestion of food (3 marks)
18. Describe three adaptations of the small intestine (ileum) that allow it to
absorb digested food efficiently (3 marks)
19. Explain what is meant by the term peristalsis. (1 mark)
20. A student carried out an experiment to find out the best conditions for the
enzyme pepsin to digest protein. For the protein, she used egg white power,
which forms a cloudy white suspension in water. The table below shows how the
tubes were set up. Three tubes were left at 37°C. Why was this temperature
chosen? (1 mark)
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