ALEVELPAPERZZ2024
A-level
BIOLOGY
7402/2
Paper 2
Mark scheme
June 2024
Version: 1.0 Final
, MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
Mark scheme instructions to examiners
1. General
The mark scheme for each question shows:
• the marks available for each part of the question
• the total marks available for the question
• the typical answer or answers which are expected
• extra information to help the examiner make his or her judgement and help to delineate what
is acceptable or not worthy of credit or, in discursive answers, to give an overview of the area
in which a mark or marks may be awarded.
The extra information in the ‘Comments’ column is aligned to the appropriate answer in the left-
hand part of the mark scheme and should only be applied to that item in the mark scheme.
At the beginning of a part of a question a reminder may be given, for example: where
consequential marking needs to be considered in a calculation; or the answer may be on the
diagram or at a different place on the script.
In general the right-hand side of the mark scheme is there to provide those extra details which
confuse the main part of the mark scheme yet may be helpful in ensuring that marking is
straightforward and consistent.
2. Emboldening
2.1 In a list of acceptable answers where more than one mark is available ‘any two from’ is
used, with the number of marks emboldened. Each of the following bullet points is a
potential mark.
2.2 A bold and is used to indicate that both parts of the answer are required to award the
mark.
2.3 Alternative answers acceptable for the same mark are indicated by the use of OR.
Different terms in the mark scheme are shown by a / ; eg allow smooth / free movement.
3. Marking points
3.1 Marking of lists
This applies to questions requiring a set number of responses, but for which students
have provided extra responses. The general principle to be followed in such a situation is
that ‘right + wrong = wrong’.
Each error / contradiction negates each correct response. So, if the number of errors /
contradictions equals or exceeds the number of marks available for the question, no
marks can be awarded.
However, responses considered to be neutral (often prefaced by ‘Ignore’ in the
‘Comments’ column of the mark scheme) are not penalised.
3
, MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
3.2 Marking procedure for calculations
Full marks can be given for a correct numerical answer, without any working shown.
However, if the answer is incorrect, mark(s) can usually be gained by correct substitution /
working and this is shown in the ‘Comments’ column or by each stage of a longer
calculation.
3.3 Interpretation of ‘it’
Answers using the word ‘it’ should be given credit only if it is clear that the ‘it’ refers to the
correct subject.
3.4 Errors carried forward, consequential marking and arithmetic errors
Allowances for errors carried forward are most likely to be restricted to calculation
questions and should be shown by the abbreviation ECF or consequential in the mark
scheme.
An arithmetic error should be penalised for one mark only unless otherwise amplified in
the mark scheme. Arithmetic errors may arise from a slip in a calculation or from an
incorrect transfer of a numerical value from data given in a question.
3.5 Phonetic spelling
The phonetic spelling of correct scientific terminology should be credited unless there is a
possible confusion with another technical term.
3.6 Brackets
(…..) are used to indicate information which is not essential for the mark to be awarded
but is included to help the examiner identify the sense of the answer required.
3.7 Ignore / Insufficient / Do not allow
Ignore or insufficient is used when the information given is irrelevant to the question or not
enough to gain the marking point. Any further correct amplification could gain the marking
point.
Do not allow means that this is a wrong answer which, even if the correct answer is
given, will still mean that the mark is not awarded.
4
,ALEVELPAPERZZ2024 MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
Question Marking Guidance Mark Comments
A = mitochondrion 4 correct = 2 marks
B = presynaptic membrane/neurone 2–3 correct = 1 mark
C = (synaptic) vesicle(s) 0–1 correct = 0 marks
D = synaptic gap/cleft;; 2 A. Accept
01.1 mitochondria/crista(e).
(2 x
AO1) B. Accept synaptic
knob/bulb or motor
neurone.
B. Accept nerve cell
for neurone.
Question Marking Guidance Mark Comments
1. Acetylcholine/neurotransmitter diffuses (across Incorrect sequence,
synaptic cleft); penalise one mark.
1 and 2. Accept
abbreviations for
2. (Acetylcholine/neurotransmitter) attaches to acetylcholine as term
receptors on the sarcolemma; is in the question.
1, 2 and 3. Accept
mark points in ‘context
3. Sodium ions enter leading to of a postsynaptic
depolarisation/action potential; neurone’.
4
2. Accept
01.2 (4 x postsynaptic
4. Calcium (ions) released by AO1) membrane for
endoplasmic/sarcoplasmic reticulum; sarcolemma.
3. Accept Na+ for
sodium ions.
3. ‘Sodium ion
channels opening’ on
its own is not enough.
4. Accept Ca2+ / Ca
(ions not required as
given in question).
Question Marking Guidance Mark Comments
1. (Inside postsynaptic neurone/membrane/axon) 1. Accept answers
is more negative 2 which refer to a
01.3 numerical decrease in
OR (2 x
AO1) the resting potential.
Membrane/neurone/axon) potential is below
resting potential
5
, MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
OR 1. Accept answers
which refer to a
Potential difference (across membrane) is
‘decrease in the
greater;
resting potential’.
2. More sodium ions (required to enter) for
1. Accept answers
depolarisation
which refer to
OR ‘reduces/lowers
More sodium ions (required to enter) for action potential’ but not
potential ‘reduces potential
difference’.
OR
1. Accept p d for
Prevents sodium ions causing depolarisation; potential difference.
2. Accept to ‘reach
threshold’ or
‘generator potential’
for ‘action potential’.
2. Accept Na+ for
sodium ions.
Question Marking Guidance Mark Comments
Correct answer of ..44 x 10–2 = 2 marks;; 10–2 is essential for
2
two marks.
02.1 Incorrect answer but shows / 544 (ignore
(2 x
position of any decimal point or
AO2)
preceding/subsequent zeros) = 1 mark;
Question Marking Guidance Mark Comments
H-zone decreases, I-band decreases, A-band no 1
02.2 change; (1 x
AO1)
Question Marking Guidance Mark Comments
1. Fast (fibres) contract quickly whereas 1. Accept fast contract
slow (fibres) contract slowly quicker OR slow
contract slower OR
OR
4 fast used for shorter
Fast (fibres) used for short time whereas time OR slow used for
02.3 (4 x
slow(fibres) used for long time; longer time.
AO2)
2. Fast (fibres mainly) use anaerobic respiration 1. Accept examples of
OR short-time / power
exercise e.g.,
Slow (fibres) use aerobic respiration; sprinting, weightlifting
6
A-level
BIOLOGY
7402/2
Paper 2
Mark scheme
June 2024
Version: 1.0 Final
, MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
Mark scheme instructions to examiners
1. General
The mark scheme for each question shows:
• the marks available for each part of the question
• the total marks available for the question
• the typical answer or answers which are expected
• extra information to help the examiner make his or her judgement and help to delineate what
is acceptable or not worthy of credit or, in discursive answers, to give an overview of the area
in which a mark or marks may be awarded.
The extra information in the ‘Comments’ column is aligned to the appropriate answer in the left-
hand part of the mark scheme and should only be applied to that item in the mark scheme.
At the beginning of a part of a question a reminder may be given, for example: where
consequential marking needs to be considered in a calculation; or the answer may be on the
diagram or at a different place on the script.
In general the right-hand side of the mark scheme is there to provide those extra details which
confuse the main part of the mark scheme yet may be helpful in ensuring that marking is
straightforward and consistent.
2. Emboldening
2.1 In a list of acceptable answers where more than one mark is available ‘any two from’ is
used, with the number of marks emboldened. Each of the following bullet points is a
potential mark.
2.2 A bold and is used to indicate that both parts of the answer are required to award the
mark.
2.3 Alternative answers acceptable for the same mark are indicated by the use of OR.
Different terms in the mark scheme are shown by a / ; eg allow smooth / free movement.
3. Marking points
3.1 Marking of lists
This applies to questions requiring a set number of responses, but for which students
have provided extra responses. The general principle to be followed in such a situation is
that ‘right + wrong = wrong’.
Each error / contradiction negates each correct response. So, if the number of errors /
contradictions equals or exceeds the number of marks available for the question, no
marks can be awarded.
However, responses considered to be neutral (often prefaced by ‘Ignore’ in the
‘Comments’ column of the mark scheme) are not penalised.
3
, MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
3.2 Marking procedure for calculations
Full marks can be given for a correct numerical answer, without any working shown.
However, if the answer is incorrect, mark(s) can usually be gained by correct substitution /
working and this is shown in the ‘Comments’ column or by each stage of a longer
calculation.
3.3 Interpretation of ‘it’
Answers using the word ‘it’ should be given credit only if it is clear that the ‘it’ refers to the
correct subject.
3.4 Errors carried forward, consequential marking and arithmetic errors
Allowances for errors carried forward are most likely to be restricted to calculation
questions and should be shown by the abbreviation ECF or consequential in the mark
scheme.
An arithmetic error should be penalised for one mark only unless otherwise amplified in
the mark scheme. Arithmetic errors may arise from a slip in a calculation or from an
incorrect transfer of a numerical value from data given in a question.
3.5 Phonetic spelling
The phonetic spelling of correct scientific terminology should be credited unless there is a
possible confusion with another technical term.
3.6 Brackets
(…..) are used to indicate information which is not essential for the mark to be awarded
but is included to help the examiner identify the sense of the answer required.
3.7 Ignore / Insufficient / Do not allow
Ignore or insufficient is used when the information given is irrelevant to the question or not
enough to gain the marking point. Any further correct amplification could gain the marking
point.
Do not allow means that this is a wrong answer which, even if the correct answer is
given, will still mean that the mark is not awarded.
4
,ALEVELPAPERZZ2024 MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
Question Marking Guidance Mark Comments
A = mitochondrion 4 correct = 2 marks
B = presynaptic membrane/neurone 2–3 correct = 1 mark
C = (synaptic) vesicle(s) 0–1 correct = 0 marks
D = synaptic gap/cleft;; 2 A. Accept
01.1 mitochondria/crista(e).
(2 x
AO1) B. Accept synaptic
knob/bulb or motor
neurone.
B. Accept nerve cell
for neurone.
Question Marking Guidance Mark Comments
1. Acetylcholine/neurotransmitter diffuses (across Incorrect sequence,
synaptic cleft); penalise one mark.
1 and 2. Accept
abbreviations for
2. (Acetylcholine/neurotransmitter) attaches to acetylcholine as term
receptors on the sarcolemma; is in the question.
1, 2 and 3. Accept
mark points in ‘context
3. Sodium ions enter leading to of a postsynaptic
depolarisation/action potential; neurone’.
4
2. Accept
01.2 (4 x postsynaptic
4. Calcium (ions) released by AO1) membrane for
endoplasmic/sarcoplasmic reticulum; sarcolemma.
3. Accept Na+ for
sodium ions.
3. ‘Sodium ion
channels opening’ on
its own is not enough.
4. Accept Ca2+ / Ca
(ions not required as
given in question).
Question Marking Guidance Mark Comments
1. (Inside postsynaptic neurone/membrane/axon) 1. Accept answers
is more negative 2 which refer to a
01.3 numerical decrease in
OR (2 x
AO1) the resting potential.
Membrane/neurone/axon) potential is below
resting potential
5
, MARK SCHEME – A-LEVEL BIOLOGY – 7402/2 – JUNE 2024
OR 1. Accept answers
which refer to a
Potential difference (across membrane) is
‘decrease in the
greater;
resting potential’.
2. More sodium ions (required to enter) for
1. Accept answers
depolarisation
which refer to
OR ‘reduces/lowers
More sodium ions (required to enter) for action potential’ but not
potential ‘reduces potential
difference’.
OR
1. Accept p d for
Prevents sodium ions causing depolarisation; potential difference.
2. Accept to ‘reach
threshold’ or
‘generator potential’
for ‘action potential’.
2. Accept Na+ for
sodium ions.
Question Marking Guidance Mark Comments
Correct answer of ..44 x 10–2 = 2 marks;; 10–2 is essential for
2
two marks.
02.1 Incorrect answer but shows / 544 (ignore
(2 x
position of any decimal point or
AO2)
preceding/subsequent zeros) = 1 mark;
Question Marking Guidance Mark Comments
H-zone decreases, I-band decreases, A-band no 1
02.2 change; (1 x
AO1)
Question Marking Guidance Mark Comments
1. Fast (fibres) contract quickly whereas 1. Accept fast contract
slow (fibres) contract slowly quicker OR slow
contract slower OR
OR
4 fast used for shorter
Fast (fibres) used for short time whereas time OR slow used for
02.3 (4 x
slow(fibres) used for long time; longer time.
AO2)
2. Fast (fibres mainly) use anaerobic respiration 1. Accept examples of
OR short-time / power
exercise e.g.,
Slow (fibres) use aerobic respiration; sprinting, weightlifting
6
