A-level
BIOLOGY
Paper 1
7402/1
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 Questio Mark
a scientific calculator. n
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.
You must answer the questions in the spaces provided. Do 5
not write outside the box around each page or on blank 6
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 8
answer(s). 9
Show all your working. 10
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 91.
final
,final
, 2
Do not write
outside the
Answer all questions in the spaces box
provided.
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
, 3
Do not write
outside the
0 2 .1 Chitin is a polysaccharide. The chitin monomer is a β-glucose molecule box
with one OH 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
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