2023 AQA A-level BIOLOGY 7402/1 Paper 1
Question Paper & Mark scheme (Merged) June
2023 [VERIFIED]
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 9
want to be marked. 10
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 91.
, 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 . 2Explain why viruses are described as acellular and non-living.
[2 marks]
0 1 . 3Give 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
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Freemann. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.36. You're not tied to anything after your purchase.