Biology Grade 11 CONFIDENTIAL

Section A
Circle the correct answer.

1. What is the main function of rod cells in the retina?

a. Color vision
b. Depth perception
c. Night vision
d. Focusing light

2. What is the primary function of the alveoli in the lungs?

a. Produce surfactant
b. Filter out dust particles
c. Gas exchange
d. Regulate breathing rate

3. Which part of the nervous system controls involuntary actions like heart rate and
digestion?
a. Central nervous system
b. Peripheral nervous system
c. Somatic nervous system
d. Autonomic nervous system

4. Which part of the eye is responsible for controlling the amount of light entering the
eye?
a. Retina
b. Cornea
c. Iris
d. Lens

5. How does the eye adjust its focus for viewing near objects?
a. The lens becomes thinner
b. The ciliary muscles relax
c. The pupil constricts
d. The lens becomes thicker

6. What is the role of the myelin sheath in neurons?

a. To produce neurotransmitters
b. To insulate the axon
c. To generate action potentials
d. To connect neurons at synapses

1
Biology Grade 11 CONFIDENTIAL

7. What is the main difference between inspired air and expired air?
a. Inspired air has more carbon dioxide than expired air
b. Expired air has a higher temperature than inspired air
c. Inspired air contains more nitrogen than expired air
d. Expired air has more oxygen than inspired air

8. Which of the following is a correct statement about auxin?

a. It inhibits cell division in all plant tissues
b. It is produced only in the roots
c. It promotes phototropism in stems
d. It decreases the flexibility of cell walls

9. How does the percentage of oxygen change from inspired to expired air?
a. It increases from about 21% to 25%
b. It decreases from about 21% to 16%
c. It remains constant at 21%
d. It decreases from about 21% to 5%

10. During inhalation, which of the following occurs?

a. The diaphragm relaxes and moves upward
b. The ribcage moves inward and downward
c. The pressure in the thoracic cavity increases
d. The volume of the lungs increases

2
Biology Grade 11 CONFIDENTIAL

Section B
Answer all questions.

1. Figure 1 shows the human head, neck and thorax.

Label the figure above with the correct name (10 marks)

3
Biology Grade 11 CONFIDENTIAL

2. Yeast cells and human muscle cells can carry out both aerobic and anaerobic
respiration.

a) Complete Table 2 by writing the end products of aerobic and anaerobic

respiration in these two types of cell. (5 marks)

Types of respiration Aerobic respiration Anaerobic respiration

Presence of oxygen
(Yes or No)

How many ATP

molecules are
produced?

What are the

products of
respiration?

4
Biology Grade 11 CONFIDENTIAL

3. The nervous system coordinates the responses of animals to changes in their

environment.

a) Figure 2 shows the arrangement of the nervous system in a mammal. Complete

Figure 2 by writing the names of the missing parts of the mammalian nervous
system in the boxes. (2 marks)

b) Figure 3 shows a flow of impulse transmitted for the reflex arc.

5
Biology Grade 11 CONFIDENTIAL

i. Label the types of neurons found at X and Y. (2 marks)

ii. Give one example of reflex arc action other than pulling away from hot plate. (1 mark)

______________________________________________________________________
______________________________________________________________________

6
Biology Grade 11 CONFIDENTIAL

5. Explain how nerve impulses are transmitted across a synapse. In your answer, describe
the role of neurotransmitters and the sequence of events that occur at the synapse
during the transmission of an impulse. (5 marks) (Tips: You can draw a diagram of the
synapses to help in the explanation)

______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________

7
Biology Grade 11 CONFIDENTIAL

6. How do endocrine disorders, such as diabetes or hyperthyroidism, affect the normal

functioning of the human body? Explain the hormonal imbalances involved and their
impact on health. (5 marks)

______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________