PDF
Mark Scheme (Results)
Summer 2026
Pearson Edexcel Advanced Level in Biology A
(Salters Nuffield)
9BN0/01
,Edexcel and BTEC Qualifications
Edexcel and BTEC qualifications are awarded by Pearson, the UK’s
largest awarding body. We provide a wide range of qualifications
including academic, vocational, occupational and specific
programmes for employers. For further information visit our
qualifications websites at www.edexcel.com or www.btec.co.uk.
Alternatively, you can get in touch with us using the details on our
contact us page at www.edexcel.com/contactus
Pearson: helping people progress, everywhere
Pearson aspires to be the world’s leading learning company. Our aim is to help 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 in education for
over 150 years, and by working across 70 countries, in 100 languages, we have built an
international reputation for our commitment to high standards and raising achievement
through innovation in education. Find out more about how we can help you and your
students at: www.pearson.com/uk
Summer 2026
Question Paper Log Number P79058A
Publication Code 9BN0_01_2606_MS
All the material in this publication is copyright
© Pearson
,General Marking Guidance
• All candidates must receive the same treatment. Examiners must mark the first
candidate in exactly the same way as they mark the last.
• Mark schemes should be applied positively. Candidates must be rewarded for what
they have shown they can do rather than penalised for omissions.
• Examiners should mark according to the mark scheme not according to their
perception of where the grade boundaries may lie.
• There is no ceiling on achievement. All marks on the mark scheme should be used
appropriately.
• All the marks on the mark scheme are designed to be awarded. Examiners should
always award full marks if deserved, i.e. if the answer matches the mark scheme.
Examiners should also be prepared to award zero marks if the candidate’s response
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.
, Question Answer Mark
Number
1(a)(i) The only correct answer is – C
A is incorrect because all the options could result in a mutation
B is incorrect because all the options could result in a mutation
D is incorrect because all the options could result in a mutation
(1)
Question Answer Mark
Number
1(a)(ii) The only correct answer is – A
B is incorrect because this has not considered the use of one triplet for a stop codon
C is incorrect because this has not considered the triplet code nature of the gene
D is incorrect because this has multiplied by 3 instead of dividing
(1)
Question Answer Additional guidance Mark
number
1(a)(iii) An explanation that makes reference to two of the following: IGNORE descriptions of degenerate code
• { triplet code / three bases / one codon } codes for one
amino acid (1)
• (genetic code is) non overlapping (1)
• stop codons do not result in the addition of an amino acid ALLOW stop codons do not code for an
/ the first amino acid (met / methionine ) is often removed amino acid
(1) (2)
Mark Scheme (Results)
Summer 2026
Pearson Edexcel Advanced Level in Biology A
(Salters Nuffield)
9BN0/01
,Edexcel and BTEC Qualifications
Edexcel and BTEC qualifications are awarded by Pearson, the UK’s
largest awarding body. We provide a wide range of qualifications
including academic, vocational, occupational and specific
programmes for employers. For further information visit our
qualifications websites at www.edexcel.com or www.btec.co.uk.
Alternatively, you can get in touch with us using the details on our
contact us page at www.edexcel.com/contactus
Pearson: helping people progress, everywhere
Pearson aspires to be the world’s leading learning company. Our aim is to help 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 in education for
over 150 years, and by working across 70 countries, in 100 languages, we have built an
international reputation for our commitment to high standards and raising achievement
through innovation in education. Find out more about how we can help you and your
students at: www.pearson.com/uk
Summer 2026
Question Paper Log Number P79058A
Publication Code 9BN0_01_2606_MS
All the material in this publication is copyright
© Pearson
,General Marking Guidance
• All candidates must receive the same treatment. Examiners must mark the first
candidate in exactly the same way as they mark the last.
• Mark schemes should be applied positively. Candidates must be rewarded for what
they have shown they can do rather than penalised for omissions.
• Examiners should mark according to the mark scheme not according to their
perception of where the grade boundaries may lie.
• There is no ceiling on achievement. All marks on the mark scheme should be used
appropriately.
• All the marks on the mark scheme are designed to be awarded. Examiners should
always award full marks if deserved, i.e. if the answer matches the mark scheme.
Examiners should also be prepared to award zero marks if the candidate’s response
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.
, Question Answer Mark
Number
1(a)(i) The only correct answer is – C
A is incorrect because all the options could result in a mutation
B is incorrect because all the options could result in a mutation
D is incorrect because all the options could result in a mutation
(1)
Question Answer Mark
Number
1(a)(ii) The only correct answer is – A
B is incorrect because this has not considered the use of one triplet for a stop codon
C is incorrect because this has not considered the triplet code nature of the gene
D is incorrect because this has multiplied by 3 instead of dividing
(1)
Question Answer Additional guidance Mark
number
1(a)(iii) An explanation that makes reference to two of the following: IGNORE descriptions of degenerate code
• { triplet code / three bases / one codon } codes for one
amino acid (1)
• (genetic code is) non overlapping (1)
• stop codons do not result in the addition of an amino acid ALLOW stop codons do not code for an
/ the first amino acid (met / methionine ) is often removed amino acid
(1) (2)
