Pearson Edexcel International Advanced Level
Friday 09 January 2026
Morning (Time: 1 hour 30 minutes)
Paper
reference WBI11/01A
Biology
International Advanced Subsidiary / Advanced Level
UNIT 1: Molecules, Diet, Transport and Health
Mark Scheme (Results)
Question paper
January 2026
You must have: Answer Book (sent separately)
Scientific calculator, ruler, HB pencil.
Do not return this question paper with the answer book.
Pearson Edexcel International Advanced
Subsidiary level In Biology
WBI11/01A
Turn over
P87611APearson Education Ltd.
C:1/1/1/1/
*P87611A*
, Answer ALL questions. Write your answers in the Answer Book. Edexcel and BTEC Qualifications
Some questions must be answered with a cross in a box in the Answer Book.
If you change your mind about an 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
largest awarding body. We provide a wide range of qualifications
1 The structure of the cell membrane controls the movement of substances into and
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
qualifications websites at or .
cell membrane.
Alternatively, you can get in touch with us using the details on our
Complete the description in the Answer Book by writing the most appropriate word contact us page at
or words on the 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
learning, for all kinds of people, wherever they are in the world. We’ve been involved
called .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................................................
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 P87611A
Publication Code WBI11_01A_2601
l the material in this publication is
Pearson Education Ltd
2 P87611A
,2 Cystic fibrosis can impair gas exchange. General Marking Guidance
(a) The rate of diffusion of gases through a surface is dependent on the properties of
the gas exchange surface. • All candidates must receive the same treatment. Examiners must mark the first
candidate in exactly the same way as they mark the last.
(i) Whose law can be used to calculate the rate of diffusion?
(1) • Mark schemes should be applied positively. Candidates must be rewarded for
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.
(3) Examiners should also be prepared to award zero marks if the candidate’s response
is not worthy of credit according to the mark scheme.
(b) Prenatal testing can be used to detect cystic fibrosis.
• Where some judgement is required, mark schemes will provide the principles by
Describe how one named method of prenatal testing can be used to detect which marks will be awarded and exemplification may be limited.
cystic fibrosis.
(3) • When examiners are in doubt regarding the application of the mark scheme to a
candidate’s response, the team leader must be consulted.
(Total for Question 2 = 7 marks)
• Crossed out work should be marked UNLESS the candidate has replaced it with an
alternative response.
P87611A 3
Turn over
, Question Answer Additional guidance Mark
3 Body mass index (BMI) can be used as an obesity indicator. number
1 An answer that makes reference to the following points :
(a) Name one other obesity indicator.
(1)
• phospholipids / phospholipid {bilayer / tail} / (hydrophobic /
(b) The table shows the BMI range for four weight categories. non-polar) fatty acid tails (1)
BMI range Weight category • facilitated diffusion (1) DO NOT ACCEPT diffusion / any
other mechanism
<18.5 underweight
• active transport (1) DO NOT ACCEPT any other
18.5 to 24.9 healthy weight
mechanisms
25 to 29.9 overweight
• ATP / carrier proteins / protein pumps (1) ACCEPT energy
>30 obese
• endocytosis (1) IGNORE pinocytosis /
phagocytosis
(i) Determine the weight category of a person who is 160 cm tall with body mass
of 76 kg. DO NOT ACCEPT any other
(1) mechanism (5)
Use the formula:
body mass in kg
BMI =
(height in m)2
(ii) Another person had a BMI of 25.2.
Explain how a person with a BMI of 25.2 could change their diet to reduce
their risk of coronary heart disease.
(3)
(Total for Question 3 = 5 marks)
4 P87611A
Friday 09 January 2026
Morning (Time: 1 hour 30 minutes)
Paper
reference WBI11/01A
Biology
International Advanced Subsidiary / Advanced Level
UNIT 1: Molecules, Diet, Transport and Health
Mark Scheme (Results)
Question paper
January 2026
You must have: Answer Book (sent separately)
Scientific calculator, ruler, HB pencil.
Do not return this question paper with the answer book.
Pearson Edexcel International Advanced
Subsidiary level In Biology
WBI11/01A
Turn over
P87611APearson Education Ltd.
C:1/1/1/1/
*P87611A*
, Answer ALL questions. Write your answers in the Answer Book. Edexcel and BTEC Qualifications
Some questions must be answered with a cross in a box in the Answer Book.
If you change your mind about an 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
largest awarding body. We provide a wide range of qualifications
1 The structure of the cell membrane controls the movement of substances into and
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
qualifications websites at or .
cell membrane.
Alternatively, you can get in touch with us using the details on our
Complete the description in the Answer Book by writing the most appropriate word contact us page at
or words on the 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
learning, for all kinds of people, wherever they are in the world. We’ve been involved
called .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................................................
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 P87611A
Publication Code WBI11_01A_2601
l the material in this publication is
Pearson Education Ltd
2 P87611A
,2 Cystic fibrosis can impair gas exchange. General Marking Guidance
(a) The rate of diffusion of gases through a surface is dependent on the properties of
the gas exchange surface. • All candidates must receive the same treatment. Examiners must mark the first
candidate in exactly the same way as they mark the last.
(i) Whose law can be used to calculate the rate of diffusion?
(1) • Mark schemes should be applied positively. Candidates must be rewarded for
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.
(3) Examiners should also be prepared to award zero marks if the candidate’s response
is not worthy of credit according to the mark scheme.
(b) Prenatal testing can be used to detect cystic fibrosis.
• Where some judgement is required, mark schemes will provide the principles by
Describe how one named method of prenatal testing can be used to detect which marks will be awarded and exemplification may be limited.
cystic fibrosis.
(3) • When examiners are in doubt regarding the application of the mark scheme to a
candidate’s response, the team leader must be consulted.
(Total for Question 2 = 7 marks)
• Crossed out work should be marked UNLESS the candidate has replaced it with an
alternative response.
P87611A 3
Turn over
, Question Answer Additional guidance Mark
3 Body mass index (BMI) can be used as an obesity indicator. number
1 An answer that makes reference to the following points :
(a) Name one other obesity indicator.
(1)
• phospholipids / phospholipid {bilayer / tail} / (hydrophobic /
(b) The table shows the BMI range for four weight categories. non-polar) fatty acid tails (1)
BMI range Weight category • facilitated diffusion (1) DO NOT ACCEPT diffusion / any
other mechanism
<18.5 underweight
• active transport (1) DO NOT ACCEPT any other
18.5 to 24.9 healthy weight
mechanisms
25 to 29.9 overweight
• ATP / carrier proteins / protein pumps (1) ACCEPT energy
>30 obese
• endocytosis (1) IGNORE pinocytosis /
phagocytosis
(i) Determine the weight category of a person who is 160 cm tall with body mass
of 76 kg. DO NOT ACCEPT any other
(1) mechanism (5)
Use the formula:
body mass in kg
BMI =
(height in m)2
(ii) Another person had a BMI of 25.2.
Explain how a person with a BMI of 25.2 could change their diet to reduce
their risk of coronary heart disease.
(3)
(Total for Question 3 = 5 marks)
4 P87611A
