Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
BIOLOGY
Paper 1
Wednesday 7 June 2023 Afternoon 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
Instructions 2
• 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.
• Do all rough work in this book. Cross through any work you do not want 9
to be marked. 10
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 91.
*jun237402101*
IB/M/Jun23/E9 7402/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Give the three structural features found in all virus particles and describe the function
of one of these features.
[2 marks]
1
2
3
Function of one named feature
0 1 . 2 Explain why viruses are described as acellular and non-living.
[2 marks]
0 1 . 3 Give one reason why antibiotics are not effective against viruses.
[1 mark]
5
*02*
IB/M/Jun23/7402/1
, 3
Do not write
outside the
0 2 . 1 Chitin is a polysaccharide. The chitin monomer is a β-glucose molecule with one OH box
group replaced by an NHCOCH3 group. NHCOCH3 can be represented by N(Ac).
Figure 1 shows the monomer that forms chitin and the chitin polymer.
Figure 1
Chitin has a similar structure to cellulose.
Use Figure 1 to describe three ways the structure of chitin is similar to the structure
of cellulose.
[3 marks]
1
2
3
Question 2 continues on the next page
Turn over ►
*03*
IB/M/Jun23/7402/1
, 4
Do not write
outside the
0 2 . 2 Chitin keeps the tracheae open in the tracheal system of gas exchange in an insect. box
Gas exchange does not occur in the tracheae.
Explain the importance of one adaptation of the gas exchange surface in the tracheal
system of an insect.
[2 marks]
0 2 . 3 Lignin is a polymer found in the walls of xylem vessels in plants. Lignin keeps the
xylem vessel open as a continuous tube.
Explain the importance of the xylem being kept open as a continuous tube.
[3 marks]
8
*04*
IB/M/Jun23/7402/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
BIOLOGY
Paper 1
Wednesday 7 June 2023 Afternoon 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
Instructions 2
• 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.
• Do all rough work in this book. Cross through any work you do not want 9
to be marked. 10
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 91.
*jun237402101*
IB/M/Jun23/E9 7402/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Give the three structural features found in all virus particles and describe the function
of one of these features.
[2 marks]
1
2
3
Function of one named feature
0 1 . 2 Explain why viruses are described as acellular and non-living.
[2 marks]
0 1 . 3 Give one reason why antibiotics are not effective against viruses.
[1 mark]
5
*02*
IB/M/Jun23/7402/1
, 3
Do not write
outside the
0 2 . 1 Chitin is a polysaccharide. The chitin monomer is a β-glucose molecule with one OH box
group replaced by an NHCOCH3 group. NHCOCH3 can be represented by N(Ac).
Figure 1 shows the monomer that forms chitin and the chitin polymer.
Figure 1
Chitin has a similar structure to cellulose.
Use Figure 1 to describe three ways the structure of chitin is similar to the structure
of cellulose.
[3 marks]
1
2
3
Question 2 continues on the next page
Turn over ►
*03*
IB/M/Jun23/7402/1
, 4
Do not write
outside the
0 2 . 2 Chitin keeps the tracheae open in the tracheal system of gas exchange in an insect. box
Gas exchange does not occur in the tracheae.
Explain the importance of one adaptation of the gas exchange surface in the tracheal
system of an insect.
[2 marks]
0 2 . 3 Lignin is a polymer found in the walls of xylem vessels in plants. Lignin keeps the
xylem vessel open as a continuous tube.
Explain the importance of the xylem being kept open as a continuous tube.
[3 marks]
8
*04*
IB/M/Jun23/7402/1
