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A-level
BIOLOGY
Paper 2
Friday 14 June 2024 Morning Time allowed: 2 hours
Materials
For Examiner’s Use
For this paper you must have:
• a ruler with millimetre measurements Question Mark
• a scientific calculator. 1
2
Instructions
• Use black ink or black ball-point pen. 3
• Fill in the boxes at the top of this page. 4
• Answer all questions. 5
• You must answer the questions in the spaces provided. Do not write
outside the box around each page or on blank pages. 6
• If you need extra space for your answer(s), use the lined pages at the end of 7
this book. Write the question number against your answer(s). 8
• Show all your working.
9
• Do all rough work in this book. Cross through any work you do not want
to be marked. 10
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 91.
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Answer all questions in the spaces provided. box
0 1 Figure 1 shows a drawing of a neuromuscular junction.
Figure 1
0 1 . 1 Name the parts labelled A to D.
[2 marks]
A
B
C
D
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, 3
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0 1 . 2 Following the release of acetylcholine into a neuromuscular junction, a muscle box
contraction occurs.
Describe the sequence of events, following the release of acetylcholine, that leads to
stimulation of this contraction.
Do not include in your answer the events following the release of calcium ions in the
myofibril.
[4 marks]
0 1 . 3 Inhibitory synapses cause hyperpolarisation in postsynaptic neurones.
Explain how this inhibits synaptic transmission.
[2 marks]
8
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0 2 . 1 box
Figure 2 shows part of a relaxed myofibril.
Figure 2
The myofibril represented in Figure 2 has 34 sarcomeres.
The length of every sarcomere is 2 µm
After contraction of this myofibril, the length of each sarcomere changed by 20%.
Use the information provided to calculate the length of the myofibril after contraction.
Give your answer in mm and in standard form.
Show your working.
[2 marks]
Answer mm
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0 2 . 2 Which statement correctly describes the changes in length in a sarcomere when a box
myofibril contracts?
Tick () one box.
[1 mark]
H-zone decreases, I-band increases, A-band decreases
H-zone increases, I-band decreases, A-band decreases
H-zone decreases, I-band decreases, A-band no change
H-zone increases, I-band increases, A-band no change
0 2 . 3 Fast muscle fibres have a higher concentration of glycogen than slow muscle fibres.
Explain how the difference in glycogen concentration is related to the different
properties of these muscle fibres.
[4 marks]
7
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0 3 . 1 box
A biologist investigated photosynthesis. They:
• measured the percentage of light absorbed by a plant when it was exposed to
different wavelengths
• measured the rate of photosynthesis at each wavelength of light.
Figure 3 shows the results they obtained.
Figure 3
Using Figure 3, what can you conclude about the relationship between:
[2 marks]
the percentage of light absorbed and the rate of photosynthesis
the colour of light and the rate of photosynthesis
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