1.
State what is meant by homeostasis.
[1 mark]
- maintaining a constant internal environment
JD SCIENCE
Homeostasis and response
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
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.
Amira is asked about homeostasis in a AQA Biology paper.
(a) [2 marks]
- includes temperature, blood glucose, water
(b) [3 marks]
- why homeostasis is needed
12.
Amira is asked about a receptor in a AQA Biology paper.
(a) [2 marks]
- part of a reflex arc
(b) [3 marks]
- why receptors are specific
13.
Amira is asked about a reflex arc in a AQA Biology paper.
(a) [2 marks]
- receptor → sensory neurone → synapse in CNS → motor neurone → effector
(b) [3 marks]
- why reflexes are fast
14.
Amira is asked about a synapse in a AQA Biology paper.
(a) [2 marks]
- neurotransmitter diffuses across
(b) [3 marks]
- why synapses only transmit in one direction
15.
Amira is asked about the eye in a AQA Biology paper.
(a) [2 marks]
- retina contains receptors
(b) [3 marks]
- why the pupil changes size
16.
Amira is asked about accommodation in a AQA 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 6.2 mmol/dm³. Calculate the percentage increase.
[3 marks]
- Final answer: 55%
19.
A person produces 1.5 dm³ of urine a day. How much in a week?
[3 marks]
- Final answer: 10.5 dm³
20.
Reaction time is 0.28 s. How far does a car travelling at 15 m/s travel in that time?
[3 marks]
- s=vt
- Final answer: 4.2 m
21.
A plant shoot bends 12° in 40 minutes. Calculate the mean rate.
[3 marks]
- Final answer: 0.3 °/min
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.
Amira carries out the reaction-time practical (ruler drop). This is a typical AQA 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
(c) [2 marks]
- anticipating the drop
24.
Amira carries out investigating phototropism with seedlings. This is a typical AQA 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.
Amira carries out testing urine or a model for glucose. This is a typical AQA 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.
Amira carries out the human nervous system observation of pupil reflex (light). This is a typical AQA 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
(c) [2 marks]
- measuring a moving pupil
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