1. Name the process of changing the shape of the lens in the eye to focus on near or distant objects.
a) Refraction b) Accommodation c) Convergence d) Phototransduction
Answer
b) Accommodation
2. What happens to skeletal muscles when we shiver ?
a) They contract and relax involuntarily
b) They expand to increase body size
c) They stop working to conserve energy
d) They produce hormones to regulate temperature
Answer
a) They contract and relax involuntarily
3. Which of the following statements regarding reflex actions is true ?
a) No electrical signals are sent to the brain.
b) The nerve impulse is initiated by the sensory neurone.
c) Spinal reflexes are controlled by the spinal cord.
d) A stimulus may or may not be present.
Answer
c) Spinal reflexes are controlled by the spinal cord.
4. Two students investigate their reaction times using a simple experiment. Student A sits with his lower arm resting on a table while Student B holds a ruler between Student A's thumb and index finger. At a random moment, Student B releases the ruler, and Student A attempts to catch it as quickly as possible. The distance the ruler falls before being caught is measured, and this measurement is then converted into a reaction time using a chart. Give the reason why the reaction the students investigate is not a reflex action.
Answer
The brain is involved.
5. Name and describe the functions of the structures labelled X, Y and Z in the figure below.
Answer
6. Identify the parts of the eye labelled X, Y and Z in the figure below.
Answer
7. Some people have myopia (short-sightedness) and wear spectacles (glasses) to correct their vision. The figure below shows how a spectacle lens can correct myopia. Explain how the spectacle lens corrects this condition.
Answer
The spectacle lens refracts (bends) light so that the rays focus on the retina.
8. Explain how the changes that happen in the person's body cause the body temperature to fall.
Answer
Both sweating and vasodilation cause a transfer of energy from the skin to the environment. Sweat on the skin evaporates, using heat energy from the skin to do so. Vasodilation results in more blood being carried to the skin's surface, where its heat can be lost to the air.