AQA GCSE Combined Science: Trilogy Biology Paper 2 (Foundation), 2023: Question 2
8 marks · Low Demand difficulty · Short Answer
Investigate the effect of visual versus auditory stimuli on human reaction time, including identifying variables, suggesting improvements, and plotting experimental data.
Practise this questionQuestion
Question text
02 A student investigated the effect of either seeing a stimulus or hearing a stimulus on
reaction time.
First, the student measured their reaction time to seeing a colour change.
This is the method used.
1. Sit in front of a computer with a reaction timer program open.
2. Press a key on the keyboard as quickly as possible when the computer screen
changes colour.
3. Record the reaction time.
4. Repeat steps 1 to 3 four more times and calculate the mean reaction time.
Next, the student measured their reaction time to hearing a sound.
This is the method used.
5. Sit in front of a computer with a reaction timer program open.
6. Press a key on the keyboard as quickly as possible when the computer
produces a sound.
7. Record the reaction time.
8. Repeat steps 5 to 7 four more times and calculate the mean reaction time.
02.1 Table 1 shows some variables in this investigation.
Table 1
Independent Dependent Control
Variable
variable variable variable
Distractions from background sounds
Reaction time
Type of stimulus
Identify each variable as an independent variable, a dependent variable or
a control variable.
Tick ( ) one box in each row on Table 1.
[3 marks]
02.2 How could the method be improved?
[1 mark]
Tick ( ) one box.
Measure the reaction time with a stopwatch.
Only test reaction time to seeing a colour change.
Repeat both methods 10 times. 8
02.3 A shorter reaction time means the student reacted faster.
The student reacted faster as each test was repeated.
Suggest one reason why the student’s reactions got faster.
[1 mark]
Table 2 shows the results.
Table 2
Mean reaction time
Method
in milliseconds
Seeing the stimulus 350
Hearing the stimulus 9 220
02.4 Complete Figure 2.
You should:
• plot the data from Table 2 as a bar chart
• label each bar
• label the y-axis.
[2 marks]
Figure 2
02.5 Compare the reaction time when seeing the stimulus with the reaction time when
hearing the stimulus.
[1 mark]
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Mark
Spec. Ref.
02.1 Independent Dependent Control
Variable
variable variable variable
Distractions from 1 AO1
background sounds 4.5.2
RPA6
Reaction time 1
Type of stimulus 1
do not accept more than one tick in any row
AO /
Question Answers Extra information Mark
Spec. Ref.
02.2 repeat both methods 10 times 1 AO3
4.5.2
4.5.1
RPA6
AO /
Spec. Ref.
02.3 any one from: 1 AO3
• practice ignore repeating 4.5.2
• fewer distractions 4.5.1
• familiarity (with test) RPA6
allow reference to effect of
caffeine
allow answers referring to
competitiveness
eg the student wanted to beat a
previous time
AO /
Spec. Ref.
02.4 2 bars correctly plotted allow a tolerance of ± ½ a small 1 AO2
and square 4.5.2 9
2 bars correctly labelled as allow any width bars touching or 4.5.1
seeing (the stimulus) and not RPA6
hearing (the stimulus) allow bars in either order
(y axis label) (mean reaction) 1
time in milliseconds / ms
AO /
Spec. Ref.
allow converse for hearing
02.5 stimulus if clearly stated
(when seeing stimulus reaction allow bigger / larger 1 AO3
time is) longer / greater / higher allow slower (reaction time) 4.5.2
allow slower (reactions) 4.5.1
allow 130 milliseconds more RPA6
ignore 130 milliseconds
unqualified
Total Question 2 8
How to answer it
Investigating Reaction Times: Sight vs. Sound
What this question tests
This question assesses your understanding of Required Practical 6 (RPA6). You need to identify different types of experimental variables, suggest improvements to experimental methods, interpret data trends, and demonstrate accurate graph-plotting skills.
Identifying Variables
Correct Answers
- Distractions: Control variable
- Reaction time: Dependent variable
- Type of stimulus: Independent variable
Exam Technique
Use these memory triggers:
- Independent: The one I change.
- Dependent: The Data I collect.
- Control: The one I keep the Constant.
Improving the Method
Correct Answer
Tick the box: Repeat both methods 10 times.
Key Knowledge
Repeating an experiment and calculating a mean makes the results more reliable and helps you identify anomalies (outliers). Measuring with a stopwatch (another option) would actually be less accurate than a computer because of the timer's own reaction time!
Explaining Faster Reactions
Correct Answers
Any one from:
- The student got more practice.
- They became more familiar with the test.
- There were fewer distractions as they went on.
Common Errors
The mark scheme says "ignore repeating". Simply saying "they repeated it" doesn't explain why the time got faster; you must mention the effect of that repetition (practice/familiarity).
Plotting the Graph
How to draw the bar chart
- Y-axis Label: Write "Mean reaction time in milliseconds" or "ms".
- X-axis Labels: Label one bar "Seeing" and the other "Hearing".
- Plotting:
• Draw the "Seeing" bar exactly to 350.
• Draw the "Hearing" bar exactly to 220.
Calculation Trap
Check the scale! On this graph, each small square on the y-axis represents 10 ms.
• 350 is halfway between 300 and 400.
• 220 is two small squares above 200.
Comparing Results
Correct Answer
Reaction time is longer / greater / higher when seeing the stimulus compared to hearing it.
Examiner Insight
When asked to "compare," don't just list the numbers from the table. You must use comparative language like "faster than" or "slower than" to show you understand the relationship between the data points.
Topics
Biology · B5: Homeostasis and Response
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Biology Paper 2 (Foundation), 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.