1. 1
   A student accidentally touches a hot saucepan handle. Within a fraction of a second, before she even feels any pain, her hand has already jerked away from the saucepan.

   (a)

   Which of the following best describes the type of response shown when the student's hand pulls away from the hot handle?

   [1 mark]

   • AA reflex action
   • BA voluntary action
   • CA hormonal response
   • DA conscious decision

   (b)

   In the reflex arc pathway that produced this response, which neurone carries the electrical impulse from the receptor to the central nervous system (CNS)?

   [1 mark]

   • AMotor neurone
   • BSensory neurone
   • CRelay neurone
   • DEffector neurone

   (c)

   Using the pathway stimulus → receptor → coordinator → effector → response, describe the role of the relay neurone and the synapses in this reflex arc, and explain why this reflex protects the student's hand from further injury.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student walks from bright sunlight into a dimly lit cinema. At first she can hardly see anything, but after a few minutes her eyes adjust and she can make out the shapes of the seats.

   (a)

   Which structure of the eye controls how much light enters, becoming wider in dim light to let more light reach the retina?

   [1 mark]

   • ASclera
   • BCornea
   • CIris
   • DOptic nerve

   (b)

   Which structure of the eye contains the light receptor cells that detect light entering the eye?

   [1 mark]

   • ACornea
   • BSuspensory ligaments
   • CCiliary muscles
   • DRetina

   (c)

   Explain, in terms of the iris, why the student's eyes need a few minutes to adjust after moving from the bright sunlight into the dim cinema.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Neuroscientists are investigating the effects of a head injury on a patient's behaviour and coordination. They study the patient's loss of function, electrically stimulate regions of a healthy volunteer's brain to observe the effects, and use MRI scanning to examine brain structure and activity, in order to build a map of which brain regions carry out which functions.

   (a)

   State three ways, described above, that neuroscientists study the brain in order to work out which regions carry out particular functions.

   [3 marks]

   (b)

   The patient in this study shows a loss of balance and muscle coordination after the injury, along with a change in personality and difficulty with conscious thought, but no change to automatic functions such as breathing or heart rate. Explain which regions of the brain are likely to have been damaged, referring to their normal functions.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A 45-year-old patient tells an optician that they struggle to read books held close to their face, though they can see distant road signs clearly. Tests show that light entering the eye from a near object is focused behind the retina rather than on it, a defect called hyperopia (long-sightedness).

   (a)

   Explain why light from a close object is focused behind the retina in this patient's eyes, and describe the process of accommodation that normally allows a healthy eye to focus clearly on both near and distant objects.

   [6 marks]

   (b)

   Evaluate the different methods available to correct this patient's hyperopia, describing how each method works to bring the point of focus back onto the retina.

   [6 marks]

   Total for question 4: 12 marks

End of questions