WJEC GCSE Biology (3400)
GCSE Biology
Answer sheet
Nervous and hormonal control
Separate mark scheme — do not issue with the student worksheet
Time guide: — · Questions: 32 · Total marks: 104
Written in WJEC style. Answer in full sentences unless a calculation is required.
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
1. State what is meant by homeostasis.
[1 mark]
- maintaining a constant internal environment
2. State what is meant by a receptor.
[1 mark]
- a cell that detects a stimulus
3. State what is meant by a reflex arc.
[1 mark]
- a rapid automatic response that does not involve conscious thought
4. State what is meant by a synapse.
[1 mark]
- a gap between two neurones
5. State what is meant by the eye.
[1 mark]
- sense organ that detects light
6. State what is meant by accommodation.
[1 mark]
- changing the lens shape to focus near or distant objects
7. State what is meant by insulin.
[1 mark]
- hormone from the pancreas that lowers blood glucose
8. State what is meant by glucagon.
[1 mark]
- hormone that raises blood glucose
9. State what is meant by Type 2 diabetes.
[1 mark]
- the body cells no longer respond properly to insulin
10. State what is meant by auxin.
[1 mark]
- plant hormone that controls phototropism
11. Owain is asked about homeostasis in a WJEC Biology paper.
(a) [2 marks]
- includes temperature, blood glucose, water
(b) [3 marks]
- why homeostasis is needed
12. Owain is asked about a receptor in a WJEC Biology paper.
(b) [3 marks]
- why receptors are specific
13. Owain is asked about a reflex arc in a WJEC Biology paper.
(a) [2 marks]
- receptor → sensory neurone → synapse in CNS → motor neurone → effector
14. Owain is asked about a synapse in a WJEC Biology paper.
(a) [2 marks]
- neurotransmitter diffuses across
(b) [3 marks]
- why synapses only transmit in one direction
15. Owain is asked about the eye in a WJEC Biology paper.
(a) [2 marks]
- retina contains receptors
(b) [3 marks]
- why the pupil changes size
16. Owain is asked about accommodation in a WJEC Biology paper.
(a) [2 marks]
- ciliary muscles and suspensory ligaments
(b) [3 marks]
- why a convex lens is needed for long sight
17. A reflex takes 0.018 s to travel 1.8 m. Calculate the speed of the impulse.
[3 marks]
- 1.8/0.018
- Final answer: 100 m/s
18. Blood glucose rises from 4.0 to 7 mmol/dm³. Calculate the percentage increase.
19. A person produces 1.5 dm³ of urine a day. How much in a week?
20. Reaction time is 0.28 s. How far does a car travelling at 15 m/s travel in that time?
21. A plant shoot bends 12° in 40 minutes. Calculate the mean rate.
22. Body temperature falls from 37.0°C to 35.5°C. Calculate the drop as a percentage of 37.0°C.
[3 marks]
- 1.5/37 × 100
- Final answer: 4.05%
23. Owain carries out the reaction-time practical (ruler drop). This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: practice / caffeine / distraction
- Dependent: catch distance / calculated time
(b) [2 marks]
- same ruler, same hand
- so the test is fair / only one variable is changed
24. Owain carries out investigating phototropism with seedlings. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: direction of light
- Dependent: direction of growth
(b) [2 marks]
- same species and age
- so the test is fair / only one variable is changed
(c) [2 marks]
- pots not rotated equally in the control
25. Owain carries out testing urine or a model for glucose. This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: sample
- Dependent: Benedict's colour
(b) [2 marks]
- same heating time
- so the test is fair / only one variable is changed
(c) [2 marks]
- not using a water bath safely
26. Owain carries out the human nervous system observation of pupil reflex (light). This is a typical WJEC required-practical style question.
(a) [2 marks]
- Independent: light intensity
- Dependent: pupil diameter
(b) [2 marks]
- same eye, same starting light
- so the test is fair / only one variable is changed
27. Compare the nervous system with the endocrine system.
[4 marks]
- nervous: fast, electrical, short-lived
- endocrine: slower, chemical hormones, longer lasting
28. Compare Type 1 diabetes with Type 2 diabetes.
[4 marks]
- Type 1: no insulin produced, insulin injections
- Type 2: cells do not respond, diet/exercise/drugs
29. Compare rods with cones.
[4 marks]
- rods: low light, black and white
- cones: colour, bright light
30. Compare phototropism with gravitropism.
[4 marks]
- phototropism is a response to light
- gravitropism is a response to gravity
31. Apply your knowledge of insulin to this situation: the pancreas does not produce enough insulin
[3 marks]
- the pancreas does not produce enough insulin
32. Apply your knowledge of glucagon to this situation: they have opposite effects
[3 marks]
- they have opposite effects