2020 BIOLOGY
PAPER 1
QUESTION
PAPER(2020)
*JUN207402101
* IB/M/Jun20/ 7402/1
E16
, Please write clearly in block capitals.
A-level
Centre Candidate
BIOLOGY
number number
Paper 1
Surname
Forename(s)
Candidate ure
Thursday
signat 4 June 2020 Morning 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
8
the end of this book. Write the question number against your
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.
*JUN207402101
* IB/M/Jun20/ 7402/1
E16
, 2
Do not
Answer all questions in the spaces write
box
provided.
0 1 Figure 1 shows a cell from the lining of the ileum specialised for
absorption of products of digestion.
SGLT1 is a carrier protein found in the cell-surface membrane of this cell, it
transports glucose and sodium ions (Na+) into the cell.
Figure 1
0 1 .1 The action of the carrier protein X in Figure 1 is linked to a membrane-
bound ATP hydrolase enzyme.
Explain the function of this ATP hydrolase.
[2 marks]
0 1 .2 The movement of Na+ out of the cell allows the absorption of
glucose into the cell lining the ileum.
Explain how.
[2 marks]
*02
IB/M/
, 3
Do not
write
outside
0 1 .3 Describe and explain two features you would expect to find in a cell
specialised for absorption.
[2 marks]
1
2
Question 1 continues on the next page
Turn over ►
*03
IB/M/