1. 1
   A child at home accidentally touches a hot oven tray with their fingertips and pulls their hand away before they consciously feel any pain.

   (a)

   Which type of neurone carries the nerve impulse from the receptor in the skin to the spinal cord?

   [1 mark]

   • ASensory neurone
   • BMotor neurone
   • CRelay neurone
   • DCiliated epithelial cell

   (b)

   In this reflex action, what is the effector?

   [1 mark]

   • AThe muscle in the arm that contracts to pull the hand away
   • BThe spinal cord
   • CThe skin receptor
   • DThe brain

   (c)

   Explain why it is important that this reflex action happens automatically, without the child consciously deciding to move their hand.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   An optician is testing a patient's eyes and asks them to look at objects in a dimly lit room and then in a brightly lit room to check how well their eyes detect different light conditions.

   (a)

   During an eye test, an optician shines a light into a patient's eye. Which part of the eye is mainly responsible for focusing light onto the retina to form a sharp image?

   [1 mark]

   • AThe optic nerve
   • BThe iris
   • CThe lens
   • DThe cornea only

   (b)

   Which type of light-sensitive cell in the retina is mainly responsible for detecting dim light?

   [1 mark]

   • ARod cells
   • BCone cells
   • CRoot hair cells
   • DPalisade cells

   (c)

   The optician then asks the patient to focus on a pen held close to their face. Explain how the eye changes shape to focus on this near object.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A patient has been admitted to hospital after suffering a stroke that damaged part of their cerebellum. Doctors note that the patient now has poor balance and struggles to coordinate smooth movements, although their memory and personality are unaffected.

   (a)

   Doctors explain to the patient's family that communication between neurones relies on structures called synapses. Describe the structure of a synapse and explain how a nerve impulse is transmitted across it.

   [3 marks]

   (b)

   Describe the roles of the cerebellum, medulla, hypothalamus and cerebral cortex, and explain why damage to the cerebellum in particular has affected this patient's balance and coordination.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A construction site safety officer is training new workers on two aspects of biology relevant to site safety: how the body reacts automatically to sudden hazards, and why some workers need corrective glasses to see hazards clearly at different distances.

   (a)

   A construction site safety officer is training new workers about how the body protects itself from injury. Describe the full pathway of a reflex action that occurs when a worker's hand unexpectedly touches a hot surface, from stimulus to response, and explain why this type of response is important for safety on site.

   [6 marks]

   (b)

   Some workers on the construction site wear glasses because they are long-sighted or short-sighted. Explain the causes of long-sightedness and short-sightedness, and describe how each condition is corrected using lenses.

   [6 marks]

   Total for question 4: 12 marks

End of questions