1. 1
   A neurologist explains to a patient recovering from a spinal injury how messages are normally coordinated around the body, describing the two main parts of the nervous system and the types of neurone involved.

   (a)

   Which two structures together make up the central nervous system (CNS)?

   [1 mark]

   • AThe brain and the spinal cord
   • BThe brain and the peripheral nerves
   • CThe spinal cord and the peripheral nerves
   • DThe sensory neurones and the motor neurones

   (b)

   Which type of neurone carries impulses from a receptor towards the central nervous system?

   [1 mark]

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

   (c)

   Describe the role of the peripheral nervous system, and explain how it differs from the central nervous system.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A trainee optician is taught the pathway that light and the resulting electrical impulses follow through the eye, from light first entering the eye to an impulse reaching the brain, without referring to any diagram.

   (a)

   Which structure first refracts (bends) light as it enters the eye?

   [1 mark]

   • ARetina
   • BPupil
   • CCornea
   • DOptic nerve

   (b)

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

   [1 mark]

   • ALens
   • BIris
   • CCornea
   • DRetina

   (c)

   Describe the roles of the lens and the optic nerve in this pathway.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A student compares two situations: one in which a person needs to react within a fraction of a second, and another in which a person's body needs to produce a slower, longer-lasting change over several minutes or hours.

   (a)

   Compare nervous and hormonal control in terms of the speed at which each produces a response, explaining why one is typically faster than the other.

   [3 marks]

   (b)

   Compare nervous and hormonal control in terms of how long the effects of each typically last, and explain, using this difference, why hormonal control is better suited to processes such as regulating the concentration of a substance in the blood over an extended period.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A person about to give an important public speech notices their heart pounding, their hands trembling and their mouth feeling dry, moments before they begin speaking.

   (a)

   Explain, referring to both the nervous system and a named hormone, how the person's body produces these physical changes before they begin speaking.

   [6 marks]

   (b)

   Explain, comparing the two, why the initial detection of the stressful situation is a nervous response while the physical changes that follow are largely a hormonal response.

   [6 marks]

   Total for question 4: 12 marks

5. 5
   A science teacher uses the example of a thermostat, which switches a heater on when a room becomes too cold and off again once the room warms back up, to introduce how the human body keeps its internal conditions stable.

   (a)

   What is the term for the maintenance of a constant internal environment in the body, as described by the thermostat analogy?

   [1 mark]

   • AHomeostasis
   • BOsmosis
   • CExcretion
   • DReproduction

   (b)

   In the thermostat analogy, and in homeostasis generally, what is meant by a 'set point'?

   [1 mark]

   • AThe point at which the system is switched off permanently
   • BThe highest possible value the system can reach
   • CThe particular value that the system works to maintain
   • DThe point at which the system stops responding to change

   (c)

   Explain, using the idea of negative feedback, how a control system such as a thermostat (or the body) responds when a condition moves away from its set point in either direction.

   [2 marks]

   Total for question 5: 4 marks

6. 6
   A gardener notices that houseplants kept on a windowsill all grow with their shoots bending towards the window, while their roots continue growing straight down into the soil.

   (a)

   What is the name given to the growth response of a plant shoot towards a light source?

   [1 mark]

   • AGravitropism
   • BPhototropism
   • COsmosis
   • DHomeostasis

   (b)

   What is the name given to the growth response of a plant root downwards, in the direction of gravity?

   [1 mark]

   • APhototropism
   • BHomeostasis
   • CTranspiration
   • DGravitropism

   (c)

   Name the plant hormone responsible for these growth responses, and state where in the shoot it is made.

   [2 marks]

   Total for question 6: 4 marks

7. 7
   During a routine check-up, a doctor taps a small hammer just below a patient's kneecap, causing the patient's lower leg to kick forward automatically, without the patient having to think about it.

   (a)

   Name, in the correct order, the five parts of a simple reflex arc involved in producing this automatic response.

   [3 marks]

   (b)

   Explain why this kind of reflex response is useful to the body, and describe the role of the synapses within the reflex arc in making sure the impulse travels in the correct direction.

   [4 marks]

   Total for question 7: 7 marks

8. 8
   A cyclist riding down a road sees a ball roll into their path from a garden, and swerves to avoid it within a fraction of a second, before consciously registering that they have done so.

   (a)

   Describe the complete pathway, from the ball entering the cyclist's field of vision to the cyclist's muscles carrying out the swerve, naming the structures and neurones involved at each stage.

   [6 marks]

   (b)

   The cyclist only becomes consciously aware that they have swerved after it has already happened. Explain why this kind of very fast, automatic response is more like a reflex action than a fully conscious decision, and explain what advantage this gives the cyclist.

   [6 marks]

   Total for question 8: 12 marks

End of questions