Practical questions
You will complete eight required practical activities if you are studying GCSE Biology and eighteen if you are studying GCSE Combined Science. You could be asked questions about the methods, safety precautions you might take, results and conclusions of these experiments.
In this Cells and Control section there are three suggested practicals:
- investigate human responses to external stimuli
- investigate reaction times
- investigate the speed of transmission of electrical impulses in the nervous system
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Sample question 1 - Foundation
Question
Describe the method used to investigate the speed of reaction times. [4 marks]
Answer (four from):
- person A holds out their hand with a gap between their thumb and first finger
- person B holds the ruler with the zero at the top of person A's thumb
- person B drops the ruler without telling Person A and they must catch it
- the number level with the top of person A's thumb is recorded in a suitable table - repeat this ten times
- swap places, and record another ten attempts
- you can use the conversion table to help convert your ruler measurements into reaction time or just record the catch distance in cm
Sample question 2 - Foundation
Question
Describe how you could adjust this method to show the effect of stimulants in reaction times. [2 marks]
Answer (two from):
- both person A and B both drink a caffeinated drink after they have measured their reaction times
- wait fifteen minutes for the caffeine to have an effect on the nervous system
- repeat the experiment and compare the results
Sample question 3 - Higher
Question
Identify the anomalous result in the table below and explain what the students should now do. [3 marks]
| Attempt | Distance on ruler (cm) | Distance on ruler (cm) |
| number | Without caffeine | With caffeine |
| 1 | 32 | 19 |
| 2 | 40 | 13 |
| 3 | 33 | 15 |
| 4 | 21 | 16 |
| Mean | 31.5 | 15.75 |
| Attempt | 1 |
|---|---|
| Distance on ruler (cm) | 32 |
| Distance on ruler (cm) | 19 |
| Attempt | 2 |
|---|---|
| Distance on ruler (cm) | 40 |
| Distance on ruler (cm) | 13 |
| Attempt | 3 |
|---|---|
| Distance on ruler (cm) | 33 |
| Distance on ruler (cm) | 15 |
| Attempt | 4 |
|---|---|
| Distance on ruler (cm) | 21 |
| Distance on ruler (cm) | 16 |
| Attempt | Mean |
|---|---|
| Distance on ruler (cm) | 31.5 |
| Distance on ruler (cm) | 15.75 |
Answer (one mark for the value and two for how to proceed):
- the anomalous result is the fourth reading without caffeine (21 cm)
- the students should ignore this value
- ideally they will repeat it
- if they cannot repeat the experiment they should calculate their mean without using this number
Sample question 4 - Higher
Question
This table shows how catch distances (centimetres) on the ruler drop test and reaction times (milliseconds) are related.
| Catch distance (cm) | Reaction time (ms) |
| 1 | 50 |
| 5 | 90 |
| 10 | 140 |
| 15 | 170 |
| 20 | 200 |
| 25 | 230 |
| 30 | 250 |
| Catch distance (cm) | 1 |
|---|---|
| Reaction time (ms) | 50 |
| Catch distance (cm) | 5 |
|---|---|
| Reaction time (ms) | 90 |
| Catch distance (cm) | 10 |
|---|---|
| Reaction time (ms) | 140 |
| Catch distance (cm) | 15 |
|---|---|
| Reaction time (ms) | 170 |
| Catch distance (cm) | 20 |
|---|---|
| Reaction time (ms) | 200 |
| Catch distance (cm) | 25 |
|---|---|
| Reaction time (ms) | 230 |
| Catch distance (cm) | 30 |
|---|---|
| Reaction time (ms) | 250 |
Draw a graph of catch distance against reaction time. [5 marks]
Answer:
- line graph not bar chart [1 mark]
- correctly plotted points [2 marks]
- two from:
- catch distance on x axis and reaction time on y axis
- suitable linear scales both starting at zero
- labelled axes with titles and units