Human Bio

Model Answer to Semester 1 HBS3AB 2010 EXAM

PART II (100 marks)


QUESTION 31 (Total 18 marks)

The diagram below shows the cerebral hemispheres of the brain, functional areas of the brain, connecting nerves and the eyes.



       
(a) A small electric shock was used to stimulate part of the brain.   This caused a muscle in the left leg to contract. Label the diagram with the X to show the area of the brain that would cause the muscle to contract.
(2 marks)

(b) The vision centre is located in the occipital lobe. Circle this area on the diagram above.

(1 mark)


(c) Recent research has suggested that adults who play video games regularly improved their eyesight.   The researchers found that playing action games, like Counter-Strike, improved the player’s contrast sensitivity.   This means that their night driving, where light is minimal, was better.   The experiment consisted of 22 University students divided into 2 groups.   One group played an action game and the other group, a game that required a lot less hand-eye coordination.   The two groups played 50 hours of their assigned game.   At the end of training, the action game players showed an average of 43 per cent improvement in their ability to discern ‘shades of gray’ while the other group showed no improvement.


(i) State the hypothesis in this experiment.

That watching action video games improves a person’s night driving ability.   (1)
(1 mark)

(ii) What is the independent variable being tested in this experiment?

Action Video Games (1)

(1 mark)
(iii) List TWO variables that were controlled during the experiment.

Even size groups (11 students), (1) 50 hours each (1) (2 marks)

(iv) Describe ONE improvement that could be made to this experiment.

Increase number of people in group, use different games (1) (1 mark)

(d) The sympathetic and parasympathetic divisions are described as...