AS BIOLOGY
ACTUAL 2025
PAPER
MERGED
WITH MARK
SCHEME
Paper 1
Please write clearly in block capitals.
Candidate number
Centre number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS BIOLOGY For Examiner’s Use
Paper 1 Question Mark
Monday 12 May 2025 Morning Time allowed: 1 hour 30 1
minutes 2
3
Materials
4
For this paper you must have:
• a ruler with millimetre measurements • a scientific calculator. 5
6
Instructions
• Use black ink or black ball-point pen. 7
• Fill in the boxes at the top of this page.
• Answer all questions. 8
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9 more resources
TOTAL
, 2
Do not
write
outside the
box
• You must answer the questions in the spaces provided. Do not write outside the box around each
page or on blank pages.
• If you need extra space for your answer(s), use the lined pages at the end of this book. Write the
question number against your answer(s).
• Show all your working.
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 75.
*jun257401101* IB/M/Jun25/G4002/V5
7401/1
• Do all rough work in this book. Cross through any work you do not want to be marked.
Answer all questions in the spaces provided.
.1 Figure 1 shows the structure of the amino acid alanine.
0 1
Figure 1
Name the NH2 and COOH groups in the amino acid.
[1 mark]
NH2
COOH
Figure 2 shows the molecule formed from alanine and another amino acid.
Figure 2
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, 3
Do not
write
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.2
0 1
Name the type of bond and the type of molecule formed when the two amino acids in
Figure 2 are joined.
[2 marks]
Type of
bond
Type of molecule
*02*
0 1
.3 Table 1 shows the R groups of six different amino acids.
Table 1
Amino acid R group Amino acid R group
Alanine CH3 Glycine H
Aspartic acid CH2COOH Serine CH2OH
Glutamine (CH2)2CONH2 Valine CH(CH3)2
Turn over ►
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, 4
Do not
write
outside the
box
Use the information in Table 1 to identify the amino acid joined to alanine in Figure 2.
[1 mark]
Question 1 continues on the next page
*03*
0 1 4 Figure 3 represents the structure of an antibody.
Figure 3
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IB/M/Jun25/7401/1
ACTUAL 2025
PAPER
MERGED
WITH MARK
SCHEME
Paper 1
Please write clearly in block capitals.
Candidate number
Centre number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS BIOLOGY For Examiner’s Use
Paper 1 Question Mark
Monday 12 May 2025 Morning Time allowed: 1 hour 30 1
minutes 2
3
Materials
4
For this paper you must have:
• a ruler with millimetre measurements • a scientific calculator. 5
6
Instructions
• Use black ink or black ball-point pen. 7
• Fill in the boxes at the top of this page.
• Answer all questions. 8
tyrionpapers.com for
9 more resources
TOTAL
, 2
Do not
write
outside the
box
• You must answer the questions in the spaces provided. Do not write outside the box around each
page or on blank pages.
• If you need extra space for your answer(s), use the lined pages at the end of this book. Write the
question number against your answer(s).
• Show all your working.
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 75.
*jun257401101* IB/M/Jun25/G4002/V5
7401/1
• Do all rough work in this book. Cross through any work you do not want to be marked.
Answer all questions in the spaces provided.
.1 Figure 1 shows the structure of the amino acid alanine.
0 1
Figure 1
Name the NH2 and COOH groups in the amino acid.
[1 mark]
NH2
COOH
Figure 2 shows the molecule formed from alanine and another amino acid.
Figure 2
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IB/M/Jun25/7401/1
, 3
Do not
write
outside the
box
.2
0 1
Name the type of bond and the type of molecule formed when the two amino acids in
Figure 2 are joined.
[2 marks]
Type of
bond
Type of molecule
*02*
0 1
.3 Table 1 shows the R groups of six different amino acids.
Table 1
Amino acid R group Amino acid R group
Alanine CH3 Glycine H
Aspartic acid CH2COOH Serine CH2OH
Glutamine (CH2)2CONH2 Valine CH(CH3)2
Turn over ►
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IB/M/Jun25/7401/1
, 4
Do not
write
outside the
box
Use the information in Table 1 to identify the amino acid joined to alanine in Figure 2.
[1 mark]
Question 1 continues on the next page
*03*
0 1 4 Figure 3 represents the structure of an antibody.
Figure 3
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IB/M/Jun25/7401/1
