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I declare this is my own work.
A-level
BIOLOGY
Paper 2
Friday 16 June 2023 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.
*jun237402201*
IB/M/Jun23/E13 7402/2
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 A student used chromatography to separate the different photosynthetic pigments in a
chlorophyll solution. She had the following materials.
Chromatography paper
A ruler and pencil
Suitable glassware
A solvent (solvent A)
2 cm3 of the chlorophyll solution
Describe how she could use these materials to separate the photosynthetic pigments
by chromatography.
[4 marks]
0 1 . 2 Using solvent A, the student separated five pigments. She then repeated her method
using a different solvent, B. Using solvent B, she separated six pigments.
Explain the difference between these results.
[2 marks]
6
*02*
IB/M/Jun23/7402/2
, 3
Do not write
outside the
0 2 . 1 Glutamate is a neurotransmitter involved in the transmission of nerve impulses from box
pain receptors to the brain. Ziconotide is a drug that can reduce severe, constant
pain. Ziconotide blocks the calcium ion channels at some of the synapses which use
glutamate.
The transmission of glutamate at synapses is similar to that of acetylcholine.
Explain how ziconotide reduces severe, constant pain.
[5 marks]
Ziconotide is a polypeptide and acts on synapses in the spinal cord. Scientists
investigated the effectiveness of ziconotide in reducing severe, constant pain.
Ziconotide was injected into each patient’s cerebrospinal fluid that bathes the brain
and spinal cord. Patients recorded the intensity of their pain using a statistically
valid scale.
0 2 . 2 Suggest two reasons why the patients had ziconotide injected into their cerebrospinal
fluid rather than taking a pill containing the drug.
[2 marks]
1
2
Question 2 continues on the next page
Turn over ►
*03*
IB/M/Jun23/7402/2
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