AQA GCSE Biology Biology Paper 2 (Foundation), November 2021: Question 4
9 marks · Low Demand difficulty · Short Answer
Label the structures of the human eye, explain how the eye accommodates for near objects, and complete a flow diagram of a blink reflex action.
Practise this questionQuestion
Question text
04 The human eye can form images of objects that are at different distances away from
the eye.
Figure 7 is a diagram of the eye.
Figure 7
04.1 Label structures A, B and C on Figure 7.
[3 marks]
Choose answers from the box.
cornea eyelid 17 iris lens optic nerve
The eye in Figure 7 is focused on a distant object.
If the eye then focuses on the words in a book, changes would occur in the eye.
The light rays would be refracted more by the lens.
04.2 How does the lens refract the light more?
[1 mark]
Tick ( ) one box.
By becoming longer
By becoming thicker
By becoming transparent
04.3 Which two structures control the shape of the lens?
[2 marks]
Tick ( ) two boxes.
Ciliary muscles
Cornea
Iris
Sclera
Suspensory ligaments
04.4 To form a clear image, the light rays entering the eye must focus on one structure in
the eye.
Name the structure.
[1 mark]
04.5 An insect flies near a person’s eye. The person blinks.
This is a reflex action.
Figure 8 shows the coordination system for this reflex action.
Figure 8
Complete Figure 8.
[2 marks]
Choose answers from the box below.
Write one word in each of boxes 2, 3 and 4 of Figure 8.
brain cornea iris muscles retina
Mark scheme
Show the mark scheme
AO /
Question Answers Extra information Mark
Spec. Ref.
04.1 A = cornea 1 AO1
4.5.2.3
B = lens 1
C = optic nerve 1
04.2 by becoming thicker 1 AO1
4.5.2.3
04.3 ciliary muscles 1 AO1
4.5.2.3
suspensory ligaments 1
04.4 retina allow rods / cones / fovea 1 AO1
4.5.2.3
04.5 in this order only 2 AO2
retina 4.5.2.1
brain
muscles
3 correct = 2 marks
1 or 2 correct = 1 mark
Total 9
How to answer it
Structure of the Eye, Accommodation & Reflex Arc
What this question tests
This question assesses foundational recall and application of Topic 5: Homeostasis and Response. Specifically, you need to identify key parts of the human eye from a diagram, explain how the eye accommodates to focus on near objects, name the structures that alter lens curvature, state where images are focused, and map out the components of a simple reflex arc (stimulus → receptor → coordinator → effector → response).
Label Structures A, B, and C
Identifying anatomical features of the human eye [3 marks]
✅ Correct Labels
- A = cornea [1 mark]
- B = lens [1 mark]
- C = optic nerve [1 mark]
💡 Visual Markers
- Cornea (A): The transparent outer curved layer at the very front of the eyeball.
- Lens (B): The transparent, biconvex disc positioned directly behind the pupil.
- Optic Nerve (C): The thick bundle of sensory neurones exiting out of the rear of the eye toward the brain.
❌ Common Errors
- Confusing the cornea (outer layer) with the lens or the sclera (white outer coat covering the rest of the eye).
- Mistaking the optic nerve for blood vessels or eye muscle attachments.
🧠 Exam Technique
- Cross off options from the provided list ( cornea, eyelid, iris, lens, optic nerve ) as you place them. Notice that "eyelid" is a distractor and is not pointed to.
Refracting Light for Near Vision
Understanding accommodation when focusing on near objects [1 mark]
✅ Correct Answer
- Tick box 2: By becoming thicker [1 mark]
💡 Physics of Accommodation
- Light rays from a near object (such as words in a book) are diverging strongly and require more refraction (bending) to converge onto the retina.
- A thicker, rounder lens provides greater optical power and refracts light rays more strongly.
❌ Common Errors
- Selecting "By becoming longer" or "By becoming transparent". The lens is already transparent; accommodation changes its thickness / curvature, not its optical clarity.
Controlling the Shape of the Lens
Identifying the antagonistic mechanism of accommodation [2 marks]
✅ Correct Answers
Tick exactly two boxes:
- Ciliary muscles [1 mark]
- Suspensory ligaments [1 mark]
💡 The Mechanism (Near Object)
- Ciliary muscles contract (reducing the internal diameter of the ring).
- Suspensory ligaments loosen / slacken.
- The lens recoils under elastic tension and becomes thicker and more rounded.
❌ Common Misconceptions
- Ticking Iris: The iris controls the diameter of the pupil (light intensity), not lens shape.
- Ticking more than two boxes: Always follow the prompt ("Tick (✓) two boxes") to avoid losing marks.
Site of Image Formation
Naming the light-sensitive structure [1 mark]
✅ Correct Answer
- retina [1 mark]
💡 Receptor Layer
- The retina is the inner light-sensitive coat containing photoreceptor cells (rods and cones).
- The fovea is the central region of the retina packed with cones where vision is sharpest.
🧠 Quick Tip
- Check the diagram in Figure 7! The label for "Retina" is already printed on the diagram, pointing to the inner back wall of the eye.
Reflex Arc Flowchart
Completing the coordination system for a blinking reflex [2 marks]
✅ Correct Order
- Box 2 (Receptor): retina
- Box 3 (Coordinator): brain
- Box 4 (Effector): muscles
1 or 2 correct = 1 mark
Note: Must be in this exact order.
💡 The Standard Reflex Pathway
- Stimulus: Light from insect
- Receptor: Retina (detects light)
- Coordinator: Brain (processes sensory impulses via optic nerve)
- Effector: Muscles (eyelid muscles contract)
- Response: The person blinks
❌ Common Errors
- Writing spinal cord instead of brain: Because the eyes are in the head, cranial reflex pathways pass directly through the brain, not the spinal cord.
- Mixing up receptor and effector: Remember that receptors detect stimuli, whereas effectors (muscles or glands) produce an action.
Topics
Biology · B5: Homeostasis and Response
Question and mark scheme from the AQA GCSE Biology examination, Biology Paper 2 (Foundation), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.