1. Name the organ that controls complex behaviour.
Answer
The brain controls complex behaviour.
2. Name the part of the brain that monitors and controls body temperature.
Answer
The thermoregulatory centre.
3. Give some examples of reflex actions.
Answer
Blinking, coughing, pupil constricting, salivating, secreting hormones, regulating heart rate, withdrawal from painful physical stimuli.
4. The figure below shows the structure of the reflex arc that causes this response. Describe how an impulse passes from neurone Y to neurone Z.
Answer
A chemical (or neurotransmitter) is released which diffuses across the synapse and attaches to receptors on the next neurone.
5. During an experiment, most of the students showed slightly faster reaction times after drinking a cup of coffee. One student concluded that caffeine decreases reaction times. Evaluate this conclusion.
Answer
The conclusion may be valid because reaction times decreased for most students. However, the conclusion may not be valid because some students' reaction times did not change. In addition, we do not know how much caffeine was in the coffee, and there might have been other substances in the coffee that affected reaction times, not just caffeine. The changes in reaction times may also have been very small. Finally, only one type of reaction was measured, so the results cannot be generalized to all reaction times.
6. Describe two other techniques that have been used to map brain function.
Answer
Electrically stimulating different parts of the brain and using MRI scanning techniques.
7. A student enters a classroom where the light is dim. The student's eye changes in response to the change in light levels. Explain how the iris brings about the change.
Answer
The radial muscles in the iris contract and the circular muscles relax. This dilates the pupil so that more light can enter.
8. The thermoregulatory centre monitors and controls body temperature. It receives information from the skin about the temperature of the environment. Describe how this information reaches the thermoregulatory centre.
Answer
Receptors in the skin detect temperature and send electrical impulses along sensory neurones to the brain's thermoregulatory centre.