AQA GCSE Biology Biology Paper 2 (Foundation), June 2025: Question 2

12 marks · Low Demand difficulty · Short Answer

Describe reflex actions, identify neurones in a reflex arc, and analyze reaction time data from a ruler-drop investigation.

Practise this question

Question

Question 2 features reflex arcs and reaction time. Part 02.1 asks for two features of a reflex action. Part 02.2 provides a diagram of a reflex arc (Figure 3) showing a finger touching a sharp object with neurones P, Q, and R, and an arm muscle; students complete sentences using terms from a box. Part 02.3 asks to match letters P, Q, and R to sensory, relay, or motor neurones. Part 02.4 asks how information travels across a synapse. Parts 02.5 to 02.7 describe a ruler-drop reaction time experiment shown in Figure 4 and Table 1 (readings 18, 17, and 13 cm), asking to calculate the mean, interpret evidence for practice improving reaction speed, and suggest an improvement.
Question text

02 Some human responses are reflex actions.

02.1 Give two features of a reflex action.

[2 marks]

Figure 3 shows the nerve pathway for moving a hand away from a sharp object.

Figure 3

02.2 Complete the sentences.

Choose answers from the box.

[2 marks]

When the finger touches the sharp object, the point

stimulates the .

Nerve impulses reach the arm muscle which is the9 .

02.3 P, Q and R in Figure 3 are three types of neurone.

Draw one line from each letter to the type of neurone.

[3 marks]

02.4 The gap between two neurones is called a synapse.

How does information travel across the synapse?

[1 mark]

Tick ( ) one box.

As a chemical

As pain

As sound 10

Two students investigated reaction time.

This is the method used.

1. Student A holds a metre rule just above student B’s hand, as shown in Figure 4.

2. Student A lets go of the metre rule.

3. Student B catches the metre rule as quickly as possible.

4. Student A writes down the reading from the scale on the metre rule.

*095. Students* A and B repeat steps 1 to 4 two more times.

Figure 4

Table 1 shows the results.

Table 1

Test Reading on metre rule in cm

1 18

2 17

3 13

Mean 11 X

02.5 Calculate mean value X in Table 1.

[2 marks]

X = cm

02.6 The students concluded:

‘Practice improved the speed of student B’s reaction.’

Give evidence for the students’ conclusion.

Use Table 1.

[1 mark]

02.7 Suggest one way to improve the investigation.

[1 mark]

Mark scheme

Show the mark scheme Mark scheme for Question 2 lists accepted answers: 02.1 requires two features (fast/rapid, protects from harm, automatic/involuntary/no conscious control); 02.2 requires 'receptor' then 'effector'; 02.3 matches P to Sensory, Q to Relay, and R to Motor; 02.4 accepts 'as a chemical'; 02.5 awards 1 mark for (18+17+13)/3 and 1 mark for 16; 02.6 accepts shorter time/distance in each successive test; 02.7 accepts improvements like more repetitions, smaller scale divisions, controlled drop height, or using a drop device. Total 12 marks.

Question 2

AO /

Question Answers Extra information Mark

Spec. Ref.

02.1 any two from: 2 AO1

4.5.2.1

• fast / rapid

• protects (from danger / harm) allow prevents harm

• a response / reaction ignore action

• automatic / involuntary allow not coordinated by the

or conscious part of the brain

not under conscious control or

allow does not involve thought /

thinking

AO /

Spec. Ref.

02.2 in this order only AO2

receptor 1 4.5.2.1

effector 1

AO /

Question Answers Mark

Spec. Ref.

02.3 AO1

4.5.2.1

do not accept more than one line from a box on the left

AO /

Spec. Ref.

02.4 as a chemical 1 AO1

4.5.2.1

AO / 9

Spec. Ref.

02.5 18 + 17 + 13 48 AO2

allow 1

33 4.5.2.1

RPA7

16 (cm) 1

AO /

Spec. Ref.

02.6 shorter time in each ignore speed / it improved 1 AO3

(successive) test 4.5.2.1

or RPA7

shorter distance in each

(successive) test

AO /

Spec. Ref.

02.7 any one from: 1 AO3

4.5.2.1

• use more repetitions RPA7

• test more students

• use ruler with smaller / mm allow use a ruler with a more

divisions precise scale

allow use a ruler with a better

resolution

ignore use a more accurate ruler

• same starting position of ruler

(above student B’s hand)

• same distance between

finger(s) and thumb

• student B supports arm / hand allow make sure student B’s

/ wrist / elbow on bench / table hand is stationary

• use same hand (each time) allow use dominant or non-

dominant hand each time

• use of mechanical / electronic allow drop ruler without warning

device to hold and drop ruler allow drop ruler at random time

intervals

allow idea of controlling

distraction / caffeine / sleep /

alcohol

allow use a computer program

Total Question 2 12

How to answer it

Reflex Arcs & the Ruler-Drop Investigation (RPA 7)

What This Question Tests

This question assesses fundamental knowledge of the human nervous system and required practical skills (RPA 7):

  • Recall: Key features of reflex actions and the mechanism of synaptic transmission.
  • Identification: Labelling components of a reflex arc (stimulus, receptor, effector, sensory/relay/motor neurones).
  • Maths & Data Skills: Calculating a simple arithmetic mean without an anomaly and interpreting drop distance data.
  • Scientific Enquiry: Evaluating an experimental method and proposing valid improvements to control variables and measurement precision.
Part 02.1 • 2 Marks

Features of a Reflex Action

AO1 (Recall of core biological concepts)

✅ Correct Answers (Any two)

  • Fast / rapid
  • Protects from harm / danger (prevents injury)
  • Automatic / involuntary (does not involve conscious thought / not coordinated by the conscious brain)
Award 1 mark for each valid feature (maximum 2 marks).

🧠 Exam Technique

Avoid circular phrasing like "it is a reflex action". Examiners look for distinct properties: speed, lack of conscious decision, and protective survival value.

Part 02.2 • 2 Marks

Completing the Reflex Sequence

AO2 (Applying knowledge to a reflex pathway)

✅ Correct Answers

1. The point stimulates the receptor [1 mark]

2. Nerve impulses reach the arm muscle which is the effector [1 mark]

Must be in this exact order. Both words taken from the provided box.

💡 Key Knowledge

Always follow the standard sequence in nervous control:

Stimulus → Receptor → Coordinator (CNS) → Effector → Response

A receptor detects a change; an effector (muscle or gland) brings about the response.

Part 02.3 • 3 Marks

Identifying Neurone Types in a Diagram

AO1 (Identifying parts of a reflex arc)

✅ Correct Matching

  • P → Sensory [1 mark]
  • Q → Relay [1 mark]
  • R → Motor [1 mark]

❌ Common Errors & Traps

  • The "Reflex" Distractor: Notice that "Reflex" is in the right-hand column. There is no such cell as a "reflex neurone"!
  • Multiple Lines: The mark scheme strictly instructs: "do not accept more than one line from a box on the left". If you draw two lines from one letter, you lose that mark.

💡 How to Identify the Neurones in Figure 3

  • P (Sensory Neurone): Carries impulses from the receptor (skin) towards the spinal cord. It has its cell body positioned off to the side in a small swelling (the dorsal root ganglion).
  • Q (Relay Neurone): Entirely enclosed inside the grey matter of the spinal cord (CNS). It connects sensory and motor neurones.
  • R (Motor Neurone): Carries electrical impulses out from the spinal cord to the effector (arm muscle).
Part 02.4 • 1 Mark

Synaptic Transmission

AO1 (Factual recall)

✅ Correct Answer

How does information travel across the synapse?

[✓] As a chemical [1 mark]

💡 Key Knowledge

Electrical impulses cannot jump across the microscopic gap (synapse) between neurones. Instead, the impulse triggers the release of a chemical neurotransmitter that diffuses across the gap and binds to receptors on the next neurone.

Part 02.5 • 2 Marks

Calculating Mean Catch Distance

AO2 / RPA 7 (Handling and processing practical data)

📐 Step-by-Step Calculation

Step 1: Add all three test readings together
18 + 17 + 13 = 48
Step 2: Divide the total by the number of tests (3)
48 ÷ 3 = 16

Answer: 16 cm

[1 mark] for showing correct method: (18 + 17 + 13) / 3 or 48 / 3.
[1 mark] for correct final answer: 16 (cm).
Part 02.6 • 1 Mark

Interpreting Experimental Evidence

AO3 (Evaluating evidence to support a conclusion)

✅ Correct Answer (Either one)

  • Shorter distance in each successive test (or distance decreases from 18 cm to 17 cm to 13 cm).
  • Shorter time taken to catch the ruler in each test.

❌ Common Misconception

Many students wrote: "The student's speed got faster."

Why this loses the mark: The question asks for evidence from Table 1 to support the claim that reaction speed improved. Table 1 only shows centimetres! You must state what actually happened to the measurements (the distance decreased).

Part 02.7 • 1 Mark

Improving the Investigation

AO3 (Experimental design and control variables)

✅ Acceptable Improvements (Any one)

  • Repeatability / Sample size: Carry out more repeats; test more students.
  • Measurement precision: Use a ruler with smaller divisions / millimetre (mm) scale.
  • Control variables:
    • Keep the ruler drop height at the exact same starting position.
    • Keep the same distance between finger and thumb.
    • Have student B rest their wrist/forearm firmly on the bench.
    • Use the same hand (e.g. dominant hand) every time.
    • Control distractions, caffeine, or ambient noise.
  • Remove human error: Use an electronic/mechanical release device or a computer-based reaction test.

🧠 Top Tip: Avoid Vague Words

Never just write "use a more accurate ruler" (the mark scheme explicitly says to ignore this). Instead, specify resolution or units: "use a ruler with millimetre divisions".

Topics

Biology · Required Practicals · B5: Homeostasis and Response · Required Practicals

Question and mark scheme from the AQA GCSE Biology examination, Biology Paper 2 (Foundation), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.