Thursday 4 June 2026 – Afternoon
A Level Biology A
H420/01 Biological processes
Time allowed: 2 hours 15 minutes
You can use:
GCE
*
• a scientific or graphical calculator
• a ruler (cm/mm)
Biology A
H420/01: Biological processes
* H 4 2 0 0 1 *
*
Please write clearly in black ink. Do not write in the barcodes. A Level
Centre number Candidate number
Mark Scheme for June 2026
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined page at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 100.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 28 pages.
ADVICE
• Read each question carefully before you start your answer.
Cambridge 2026 [601/4260/1] Cambridge is an exempt Charity
DC (WW/SW) 359625/6 Turn over
Cambridge
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Cambridge is a leading UK awarding body, providing a wide range of qualifications to
Write your answer to each question in the box provided.
meet the needs of candidates of all ages and abilities. Cambridge qualifications include
AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills,
1 Which statement about differential stains is correct? Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT,
business, languages, teaching/training, administration and secretarial skills.
A They are only used to stain living specimens.
It is also responsible for developing new specifications to meet national requirements and the
B They only stain the cell surface membrane. needs of students and teachers. Cambridge is a not-for-profit organisation; any surplus
made is invested back into the establishment to help towards the development of qualifications
C They stain all parts of a cell. and support, which keep pace with the changing needs of today’s society.
D They stain specific cell structures. This mark scheme is published as an aid to teachers and students, to indicate the requirements
of the examination. It shows the basis on which marks were awarded by examiners. It does not
Your answer [1] indicate the details of the discussions which took place at an examiners’ meeting before marking
commenced.
All examiners are instructed that alternative correct answers and unexpected approaches in
2 The table compares light and transmission electron microscopes. candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills
demonstrated.
Transmission electron
Feature Light microscope
microscope (TEM) Mark schemes should be read in conjunction with the published question papers and the report
on the examination.
Resolution 200 nm 0.5 nm
Magnification up to 2000 × more than 500 000 ×
Cambridge 2026
Ribosomes are approximately 20 nm in diameter.
Based on the information in the table, which statement is correct?
A Ribosomes can be seen in micrographs taken with a light microscope if the micrograph is
enlarged on a scanner or photocopier.
B Ribosomes can be seen in micrographs taken with a TEM but not a light microscope.
C Ribosomes can be seen in micrographs taken with either a light microscope or a TEM.
D Ribosomes cannot be seen in a micrograph taken with either a light microscope or a TEM.
Your answer [1]
Cambridge 2026
Cambridge
, H420/01 Mark Scheme June 2026
3 Marking Instructions
3 Which statement describes the formation of a DNA polynucleotide? Preparation For Marking
1. RM Assessor
A Deoxyribonucleotides bond together via purines in condensation reactions.
• Access and complete the on-screen marking training packages: Examiner Training (RMA3).
B Many deoxyribonucleotides join forming a sugar phosphate backbone.
• Read the mark scheme and question paper for this component or unit.
C Many ribonucleotides join forming a sugar phosphate backbone.
• The mark scheme and question paper are available in RM Assessor or on your Component Page if you use the Training Platform for standardisation.
D Ribonucleotides bond together via purines in condensation reactions.
• Log in to RM Assessor and mark the required number of practice scripts and the required number of standardisation scripts.
Your answer [1]
Marking
2. General Guidance
4 Which process happens during breathing out at rest?
• Mark strictly to the mark scheme.
A Elastic fibres in the walls of the alveoli recoil.
B The diaphragm contracts. • Marks awarded must relate directly to the marking criteria.
C The external intercostal muscles contract. • If you are in any doubt about applying the mark scheme, consult your Team Leader by phone, email or via the RM Assessor messaging system.
D The internal intercostal muscles contract. • It is essential that you meet the RM Assessor 50% and 100% batch deadlines. For traditional marking this will be 40% and 100%. If you experience
problems, contact your Team Leader without delay.
Your answer [1]
• Always check the pages (and additional objects if present) at the end of the response in case any answers have been continued there. If the candidate
has continued an answer there, then add the annotation ‘SEEN’ to confirm that the work has been seen and mark any responses using the annotations
in Section 6.
5 Which statement about the mammalian gas exchange system is correct?
• The RM Assessor comments box is used by your Team Leader to explain the marking of the practice responses. Use these comments when checking
A Cartilage supports the walls of the alveoli to prevent collapse during inspiration. your practice responses. Do not use the comments box for any other reason.
B Goblet cells line the alveoli and secrete mucus to trap dust particles and bacteria.
• Before the end of the marking period send a brief report on the performance of candidates to your Team Leader via email. The report should contain
C Smooth muscle in the walls of bronchioles contracts to control air flow into alveoli. notes on strengths displayed as well as common errors or weaknesses. Constructive criticism of the question paper/mark scheme is also appreciated.
2
D Trachea divide to form many small tracheoles that carry air to the alveoli.
Your answer [1]
Cambridge 2026 Turn over
A Level Biology A
H420/01 Biological processes
Time allowed: 2 hours 15 minutes
You can use:
GCE
*
• a scientific or graphical calculator
• a ruler (cm/mm)
Biology A
H420/01: Biological processes
* H 4 2 0 0 1 *
*
Please write clearly in black ink. Do not write in the barcodes. A Level
Centre number Candidate number
Mark Scheme for June 2026
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined page at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 100.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 28 pages.
ADVICE
• Read each question carefully before you start your answer.
Cambridge 2026 [601/4260/1] Cambridge is an exempt Charity
DC (WW/SW) 359625/6 Turn over
Cambridge
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Cambridge is a leading UK awarding body, providing a wide range of qualifications to
Write your answer to each question in the box provided.
meet the needs of candidates of all ages and abilities. Cambridge qualifications include
AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills,
1 Which statement about differential stains is correct? Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT,
business, languages, teaching/training, administration and secretarial skills.
A They are only used to stain living specimens.
It is also responsible for developing new specifications to meet national requirements and the
B They only stain the cell surface membrane. needs of students and teachers. Cambridge is a not-for-profit organisation; any surplus
made is invested back into the establishment to help towards the development of qualifications
C They stain all parts of a cell. and support, which keep pace with the changing needs of today’s society.
D They stain specific cell structures. This mark scheme is published as an aid to teachers and students, to indicate the requirements
of the examination. It shows the basis on which marks were awarded by examiners. It does not
Your answer [1] indicate the details of the discussions which took place at an examiners’ meeting before marking
commenced.
All examiners are instructed that alternative correct answers and unexpected approaches in
2 The table compares light and transmission electron microscopes. candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills
demonstrated.
Transmission electron
Feature Light microscope
microscope (TEM) Mark schemes should be read in conjunction with the published question papers and the report
on the examination.
Resolution 200 nm 0.5 nm
Magnification up to 2000 × more than 500 000 ×
Cambridge 2026
Ribosomes are approximately 20 nm in diameter.
Based on the information in the table, which statement is correct?
A Ribosomes can be seen in micrographs taken with a light microscope if the micrograph is
enlarged on a scanner or photocopier.
B Ribosomes can be seen in micrographs taken with a TEM but not a light microscope.
C Ribosomes can be seen in micrographs taken with either a light microscope or a TEM.
D Ribosomes cannot be seen in a micrograph taken with either a light microscope or a TEM.
Your answer [1]
Cambridge 2026
Cambridge
, H420/01 Mark Scheme June 2026
3 Marking Instructions
3 Which statement describes the formation of a DNA polynucleotide? Preparation For Marking
1. RM Assessor
A Deoxyribonucleotides bond together via purines in condensation reactions.
• Access and complete the on-screen marking training packages: Examiner Training (RMA3).
B Many deoxyribonucleotides join forming a sugar phosphate backbone.
• Read the mark scheme and question paper for this component or unit.
C Many ribonucleotides join forming a sugar phosphate backbone.
• The mark scheme and question paper are available in RM Assessor or on your Component Page if you use the Training Platform for standardisation.
D Ribonucleotides bond together via purines in condensation reactions.
• Log in to RM Assessor and mark the required number of practice scripts and the required number of standardisation scripts.
Your answer [1]
Marking
2. General Guidance
4 Which process happens during breathing out at rest?
• Mark strictly to the mark scheme.
A Elastic fibres in the walls of the alveoli recoil.
B The diaphragm contracts. • Marks awarded must relate directly to the marking criteria.
C The external intercostal muscles contract. • If you are in any doubt about applying the mark scheme, consult your Team Leader by phone, email or via the RM Assessor messaging system.
D The internal intercostal muscles contract. • It is essential that you meet the RM Assessor 50% and 100% batch deadlines. For traditional marking this will be 40% and 100%. If you experience
problems, contact your Team Leader without delay.
Your answer [1]
• Always check the pages (and additional objects if present) at the end of the response in case any answers have been continued there. If the candidate
has continued an answer there, then add the annotation ‘SEEN’ to confirm that the work has been seen and mark any responses using the annotations
in Section 6.
5 Which statement about the mammalian gas exchange system is correct?
• The RM Assessor comments box is used by your Team Leader to explain the marking of the practice responses. Use these comments when checking
A Cartilage supports the walls of the alveoli to prevent collapse during inspiration. your practice responses. Do not use the comments box for any other reason.
B Goblet cells line the alveoli and secrete mucus to trap dust particles and bacteria.
• Before the end of the marking period send a brief report on the performance of candidates to your Team Leader via email. The report should contain
C Smooth muscle in the walls of bronchioles contracts to control air flow into alveoli. notes on strengths displayed as well as common errors or weaknesses. Constructive criticism of the question paper/mark scheme is also appreciated.
2
D Trachea divide to form many small tracheoles that carry air to the alveoli.
Your answer [1]
Cambridge 2026 Turn over
