As biology 2023 abc
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
BIOLOGY
Paper 1
Monday 15 May 2023 Morning Time allowed: 1 hour 30 minutes
Materials For Examiner’s Use
For this paper you must have:
a ruler with millimetre measurements Question Mark
a scientific calculator. 1
2
Instructions
3
Use black ink or black ball-point pen.
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 6
outside the box around each page or on blank pages.
7
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). 8
Show all your working. 9
Do all rough work in this book. Cross through any work you do not want
to be marked. TOTAL
Information
The marks for the questions are shown in brackets.
The maximum mark for this paper is 75.
IB/M/Jun23/E8 7401/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Describe the primary structure of all proteins.
[2 marks]
0 1 . 2 This question is about the genetic code.
Define universal, non-overlapping and degenerate.
[3 marks]
Universal
Non-overlapping
Degenerate
5
IB/M/Jun23/7401/1
, 3
Do not write
outside the
0 2 Figure 1 shows a transmission electron microscope (TEM) image of a Streptococcus box
bacterium.
Figure 1
0 2 . 1 Describe how the appearance of the area containing DNA in a TEM image of a
eukaryotic cell would differ from that shown in Figure 1.
[2 marks]
0 2 . 2 Describe one difference between the structure of DNA in a prokaryotic cell and in a
eukaryotic cell.
[1 mark]
Question 2 continues on the next page
Turn over ►
IB/M/Jun23/7401/1
, 4
Do not write
outside the
0 2 . 3 Streptococcus bacteria can infect the lungs when air is breathed in and cause lung box
disease.
Describe the mechanism of breathing that causes air to enter the lungs.
[3 marks]
0 2 . 4 Some strains of Streptococcus bacteria are more likely to cause lung disease than
other strains.
Strains that do not cause lung disease are quickly destroyed by phagocytes.
Phagocytes are stimulated when they bind to murein on Streptococcus bacteria.
Each strain of Streptococcus bacteria has a capsule of different thickness from the
others.
Suggest how Streptococcus bacteria with a thicker capsule are more likely to survive
and so cause lung disease.
[2 marks]
8
IB/M/Jun23/7401/1
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
BIOLOGY
Paper 1
Monday 15 May 2023 Morning Time allowed: 1 hour 30 minutes
Materials For Examiner’s Use
For this paper you must have:
a ruler with millimetre measurements Question Mark
a scientific calculator. 1
2
Instructions
3
Use black ink or black ball-point pen.
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 6
outside the box around each page or on blank pages.
7
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). 8
Show all your working. 9
Do all rough work in this book. Cross through any work you do not want
to be marked. TOTAL
Information
The marks for the questions are shown in brackets.
The maximum mark for this paper is 75.
IB/M/Jun23/E8 7401/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Describe the primary structure of all proteins.
[2 marks]
0 1 . 2 This question is about the genetic code.
Define universal, non-overlapping and degenerate.
[3 marks]
Universal
Non-overlapping
Degenerate
5
IB/M/Jun23/7401/1
, 3
Do not write
outside the
0 2 Figure 1 shows a transmission electron microscope (TEM) image of a Streptococcus box
bacterium.
Figure 1
0 2 . 1 Describe how the appearance of the area containing DNA in a TEM image of a
eukaryotic cell would differ from that shown in Figure 1.
[2 marks]
0 2 . 2 Describe one difference between the structure of DNA in a prokaryotic cell and in a
eukaryotic cell.
[1 mark]
Question 2 continues on the next page
Turn over ►
IB/M/Jun23/7401/1
, 4
Do not write
outside the
0 2 . 3 Streptococcus bacteria can infect the lungs when air is breathed in and cause lung box
disease.
Describe the mechanism of breathing that causes air to enter the lungs.
[3 marks]
0 2 . 4 Some strains of Streptococcus bacteria are more likely to cause lung disease than
other strains.
Strains that do not cause lung disease are quickly destroyed by phagocytes.
Phagocytes are stimulated when they bind to murein on Streptococcus bacteria.
Each strain of Streptococcus bacteria has a capsule of different thickness from the
others.
Suggest how Streptococcus bacteria with a thicker capsule are more likely to survive
and so cause lung disease.
[2 marks]
8
IB/M/Jun23/7401/1
