Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Friday 09 January 2026 Mark Scheme (Results)
Morning (Time: 1 hour 30 minutes) Paper
reference WBI11/01
Biology
International Advanced Subsidiary / Advanced Level
UNIT 1: Molecules, Diet, Transport and Health January 2026
You must have:
Pearson Edexcel International Advanced
Total Marks
Scientific calculator, ruler, HB pencil
Subsidiary level In Biology
WBI11/01
Instructions
•• Use black ink or ball‑point pen.
Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
•• Calculators may be used.
You must show all your working out with your answer clearly identified at the
end of your solution.
Information
•• The total mark for this paper is 80.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• Into the questions marked with an asterisk (*), marks will be awarded for your ability
structure your answer logically, showing how the points you make are related or
follow on from each other where appropriate.
Advice
•• Read each question carefully before you start to answer it.
Try to answer every question.
• Check your answers if you have time at the end. Turn over
P79030APearson Education Ltd.
C:1/1/1/1/1/1/
*P79030A0132*
, Answer ALL questions. Write your answers in the spaces provided.
Edexcel and BTEC Qualifications
Some questions must be answered with a cross in a box . If you change your mind about an
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answer, put a line through the box and then mark your new answer with a cross . Edexcel and BTEC qualifications are awarded by Pearson, the UK’s
1 The structure of the cell membrane controls the movement of substances into and largest awarding body. We provide a wide range of qualifications
out of the cell. including academic, vocational, occupational and specific
programmes for employers. For further information visit our
Read through the following description of how substances move through the
cell membrane. qualifications websites at or .
Alternatively, you can get in touch with us using the details on our
Complete the description by writing the most appropriate word or words on the contact us page at
dotted lines.
The ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................. prevents large polar molecules
from passing through the membrane.
If there is a concentration gradient, these molecules can pass through protein
channels by a process called . . . . . . . . . . . . ................................................................................................................ . Pearson: helping people progress, everywhere
Pearson aspires to be the world’s leading learning company. Our aim is to help
Some substances are transported against a concentration gradient by a process
everyone progress in their lives through education. We believe in every kind of
called .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................................................... . learning, for all kinds of people, wherever they are in the world. We’ve been involved
in education for over 150 years, and by working across 70 countries, in 100
This process requires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................................................................................... . languages, we have built an international reputation for our commitment to high
standards and raising achievement through innovation in education. Find out more
Larger substances are taken into the cell when the cell membrane forms a vesicle about how we can help you and your students at:
around them.
This process is called . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................................................................................... .
(Total for Question 1 = 5 marks)
January 2026
Question Paper Log Number P79030A
Publication Code WBI11_01_2601_
l the material in this publication is
Pearson Education Ltd
2
*P79030A0232*
, General Marking Guidance
2 Cystic fibrosis can impair gas exchange.
(a) The rate of diffusion of gases through a surface is dependent on the properties of • All candidates must receive the same treatment. Examiners must mark the first
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the gas exchange surface.
candidate in exactly the same way as they mark the last.
(i) Whose law can be used to calculate the rate of diffusion? • Mark schemes should be applied positively. Candidates must be rewarded for
(1)
what they have shown they can do rather than penalised for omissions.
A Benedict’s
• Examiners should mark according to the mark scheme not according to their
B Fick’s perception of where the grade boundaries may lie.
C Meselson’s • There is no ceiling on achievement. All marks on the mark scheme should be used
appropriately.
D Stahl’s
• All the marks on the mark scheme are designed to be awarded. Examiners should
(ii) Explain how the rate of diffusion through gas exchange surfaces is affected by always award full marks if deserved, i.e. if the answer matches the mark scheme.
cystic fibrosis. Examiners should also be prepared to award zero marks if the candidate’s response
(3)
is not worthy of credit according to the mark scheme.
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • Where some judgement is required, mark schemes will provide the principles by
which marks will be awarded and exemplification may be limited.
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
• When examiners are in doubt regarding the application of the mark scheme to a
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . candidate’s response, the team leader must be consulted.
• Crossed out work should be marked UNLESS the candidate has replaced it with an
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
alternative response.
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
*P79030A0332* Turn over
, Question Answer Additional guidance Mark
number
(b) Prenatal testing can be used to detect cystic fibrosis.
1 An answer that makes reference to the following points :
Describe how one named method of prenatal testing can be used to detect
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cystic fibrosis. • phospholipids / phospholipid {bilayer / tail} / (hydrophobic /
(3)
non-polar) fatty acid tails (1)
Method of prenatal testing
• facilitated diffusion (1) DO NOT ACCEPT diffusion / any
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
other mechanism
Description of method
• active transport (1) DO NOT ACCEPT any other
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mechanisms
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • ATP / carrier proteins / protein pumps (1) ACCEPT energy
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
• endocytosis (1) IGNORE pinocytosis /
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
phagocytosis
DO NOT ACCEPT any other
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mechanism (5)
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Total for Question 2 = 7 marks)
4
*P79030A0432*