PMT

GCSE
BIOLOGY
8461/1H
Paper 1 Higher Tier
Mark scheme
June 2023
Version: 1.0 Final

*236G84611H/MS*
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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant
questions, by a panel of subject teachers. This mark scheme includes any amendments made at the
standardisation events which all associates participate in and is the scheme which was used by them in
this examination. The standardisation process ensures that the mark scheme covers the students’
responses to questions and that every associate understands and applies it in the same correct way.
As preparation for standardisation each associate analyses a number of students’ scripts. Alternative
answers not already covered by the mark scheme are discussed and legislated for. If, after the
standardisation process, associates encounter unusual answers which have not been raised they are
required to refer these to the Lead Examiner.

It must be stressed that a mark scheme is a working document, in many cases further developed and
expanded on the basis of students’ reactions to a particular paper. Assumptions about future mark
schemes on the basis of one year’s document should be avoided; whilst the guiding principles of
assessment remain constant, details will change, depending on the content of a particular examination
paper.

Further copies of this mark scheme are available from aqa.org.uk

Copyright information
AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy material from this booklet for their own
internal use, with the following important exception: AQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third
party even for internal use within the centre.

Copyright © 2023 AQA and its licensors. All rights reserved.

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

Information 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 their judgement
• the Assessment Objectives and specification content that each question is intended to cover.

The extra information 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 (for example, a scientifically correct answer that could not reasonably be expected from a
student’s knowledge of the specification).

2. Emboldening and underlining

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 a mark are indicated by the use of or.
Alternative words in the mark scheme are shown by a solidus eg allow smooth / free movement.

2.4 Any wording that is underlined is essential for the marking point to be awarded.

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

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 (indicated as * in example 1) are not penalised.

Example 1: What is the pH of an acidic solution?

[1 mark]

Student Response Marks

awarded
1 green, 5 0
2 red*, 5 1
3 red*, 8 0

Example 2: Name two magnetic materials.

[2 marks]

Student Response Marks awarded

1 iron, steel, tin 1
2 cobalt, nickel, nail* 2

3.2 Use of symbols / formulae

If a student writes a chemical symbol / formula instead of a required chemical name, or uses
symbols to denote quantities in a physics equation, full credit can be given if the symbol / formula
is correct and if, in the context of the question, such action is appropriate.

3.3 Marking procedure for calculations

Marks should be awarded for each stage of the calculation completed correctly, as students are
instructed to show their working. At any point in a calculation students may omit steps from their
working. If a subsequent step is given correctly, the relevant marks may be awarded.

Full marks are not awarded for a correct final answer from incorrect working.

3.4 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.

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

3.5 Errors carried forward

An error can be carried forward from one question part to the next and is shown by the
abbreviation ‘ecf’.

Within an individual question part, an incorrect value in one step of a calculation does not prevent
all of the subsequent marks being awarded.

3.6 Phonetic spelling

Marks should be awarded if spelling is not correct but the intention is clear, unless there is a
possible confusion with another technical term.

3.7 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.

3.8 Allow

In the mark scheme additional information, ‘allow’ is used to indicate creditworthy

alternative answers.

3.9 Ignore

Ignore 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.

3.10 Do not accept

Do not accept means that this is a wrong answer which, even if the correct answer is given as
well, will still mean that the mark is not awarded.

3.11 Numbered answer lines

Numbered lines on the question paper are intended to support the student to give the correct
number of responses. The answer should still be marked as a whole.

4. Level of response marking instructions

Extended response questions are marked on level of response mark schemes.
• Level of response mark schemes are broken down into levels, each of which has a descriptor.
• The descriptor for the level shows the average performance for the level.
• There are two marks in each level.

Before you apply the mark scheme to a student’s answer, read through the answer and, if
necessary, annotate it (as instructed) to show the qualities that are being looked for. You can then
apply the mark scheme.

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

Step 1: Determine a level

Start at the lowest level of the mark scheme and use it as a ladder to see whether the answer meets
the descriptor for that level.

The descriptor for the level indicates the different qualities that might be seen in the student’s
answer for that level. If it meets the lowest level then go to the next one and decide if it meets this
level, and so on, until you have a match between the level descriptor and the answer. With practice
and familiarity you will find that for better answers you will be able to quickly skip through the lower
levels of the mark scheme.

When assigning a level you should look at the overall quality of the answer. Do not look to penalise
small and specific parts of the answer where the student has not performed quite as well as the rest.
If the answer covers different aspects of different levels of the mark scheme you should use a best
fit approach for defining the level.

Use the variability of the response to help decide the mark within the level, ie if the response is
predominantly level 2 with a small amount of level 3 material it would be placed in level 2 but be
awarded a mark near the top of the level because of the level 3 content.

Step 2: Determine a mark

Once you have assigned a level you need to decide on the mark. The descriptors on how to
allocate marks can help with this. The exemplar materials used during standardisation will help.
There will be an answer in the standardising materials which will correspond with each level of the
mark scheme. This answer will have been awarded a mark by the Lead Examiner. You can
compare the student’s answer with the example to determine if it is the same standard, better or
worse than the example. You can then use this to allocate a mark for the answer based on the Lead
Examiner’s mark on the example.

You may well need to read back through the answer as you apply the mark scheme to clarify points
and assure yourself that the level and the mark are appropriate.

Indicative content in the mark scheme is provided as a guide for examiners. It is not intended to be
exhaustive and you must credit other valid points. Students do not have to cover all of the points
mentioned in the indicative content to reach the highest level of the mark scheme.

You should ignore any irrelevant points made. However, full marks can be awarded only if there are
no incorrect statements that contradict a correct response.

An answer which contains nothing of relevance to the question must be awarded no marks.

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

Question 1

AO /
Question Answers Extra information Mark
Spec Ref.
01.1 a group of the same / similar ignore a group of cells 1 AO1
cells unqualified 4.2.1
or
a group of cells with a (similar / ignore examples of tissue
specific) function functions

AO /
Question Answers Extra information Mark
Spec Ref.
01.2 meristem (tissue) 1 AO1
4.1.1.4
4.1.2.3
4.2.3.1

AO /
Question Answers Extra information Mark
Spec Ref.
01.3 willow ignore named parts of willow 1 AO1
4.3.1.9

AO /
Question Answers Extra information Mark
Spec Ref.
01.4 any one from: 1 AO3
4.2.3.1
• (berries are) easy to access / ignore berries are not
pick underground
• easier to extract chemical
• taking berries will not harm allow taking leaves / roots might
the plant damage / kill the plant (so it
cannot produce more chemical)
allow idea that the lower mass /
amount (of chemical) will be less
toxic / harmful
allow greater mass of berries
than of leaves / roots

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
allow conversion to mg at any
01.5 AO2
point in calculation
4.3.3.1
(0.6 × 1.2 =) 0.72 1

(0.72 × 2 =) 1.44 1

1.44 × 1000 allow conversion of a correct 1

mass calculated for berries /
roots

1440 (mg) allow a correct answer using an 1

incorrect conversion factor of a
multiple of 10

alternative route
(2 × 1.2 =) 2.4 (1)
(2.4 × 0.6 =) 1.44 (1)
1.44 × 1000 (1)
1440 (mg) (1)

AO /
Question Answers Extra information Mark
Spec Ref.
01.6 any one from: 1 AO1
4.3.3.1
• lack of chlorophyll allow lack of chloroplasts
4.3.1.2
4.3.1.4
• lack of magnesium (ions) allow lack of mineral (ions) or
named example such as iron /
nitrate / potassium / zinc (ions)
ignore lack of nutrients /
nitrogen
allow lack of water
allow incorrect pH of soil
allow acidic / alkaline soil
allow (named) infection
allow lack of light
allow other correct suggestions

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
01.7 any two from: 2 AO1
4.3.1.9
• to check toxicity allow to check it is safe
allow to check for side effects
allow to check it is not
poisonous / dangerous / harmful

• to check dosage allow to check how much is

needed

• to check its efficacy allow to check it works

allow to check it does not
interact with other drugs

AO /
Question Answers Extra information Mark
Spec Ref.
01.8 (writers / companies may get) 1 AO3
financial gain 4.3.1.9
or
(competitor may suffer) financial
loss
ignore because the report has
not been peer reviewed
ignore have not used a double-
blind trial

AO /
Question Answers Extra information Mark
Spec Ref.
01.9 have the claims peer reviewed 1 AO1
4.3.1.9

Total Question 1 13

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

Question 2

AO /
Question Answers Extra information Mark
Spec Ref.
02.1 A 1 AO1
4.2.2.2

AO /
Question Answers Extra information Mark
Spec Ref.
02.2 C 1 AO1
4.2.2.2

AO /
Question Answers Extra information Mark
Spec Ref.
02.3 right atrium 1 AO1
4.2.2.2

AO /
Question Answers Extra information Mark
Spec Ref.
allow converse if clearly
02.4 AO1
referring to a vein
4.2.2.2
any two from: 2

• (artery) has a thicker muscle

(tissue) if neither mark awarded
• (artery) has a thicker elastic allow 1 mark for artery
(tissue) has a thicker wall

• (artery) has a narrower lumen allow description of lumen

• (artery) does not contain

valves

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
02.5 as the percentage of the allow converse 1 AO2
(coronary) artery that is blocked 4.2.2.2
allow the greater the blockage,
increases, blood flow decreases
the less blood flows

allow negative correlation or

inversely proportional

allow as one increases, the

other decreases

AO /
Question Answers Extra information Mark
Spec Ref.
02.6 scale on y-axis must take up at least 50% of 1 AO2
axis 4.2.2.2

all points plotted allow 3 or 4 correct plots for 1 2

mark
allow a tolerance of ± ½ small
square

correct curved line of best fit ignore line joined point to point 1
with straight lines
ignore extrapolation

AO /
Question Answers Extra information Mark
Spec Ref.
02.7 correct answer from student's allow a tolerance of ± ½ small 1 AO3
line in Figure 3 square 4.2.2.2
if no line drawn on Figure 3,
allow a value from 18 to 24
(cm3/minute)

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Mark
Spec Ref.
02.8 Level 3: Relevant points (reasons / causes) are identified, given in 5-6 AO1
detail and logically linked to form a clear account. AO2
4.2.2.2
Level 2: Relevant points (reasons / causes) are identified, and 3-4 4.2.2.4
there are attempts at logical linking. The resulting account is not
4.4.2.1
fully clear.
4.4.2.2
Level 1: Points are identified and stated simply, but their relevance 1-2
is not clear and there is no attempt at logical linking.

No relevant content. 0

Indicative content:

• reduced blood flow to heart (muscle / tissue / cells)

• (so) less oxygen to heart (muscle / tissue / cells)
• (so) less glucose to heart (muscle / tissue / cells)

• (so) less (aerobic) respiration (in heart / body cells)

• (more) anaerobic respiration
• (so) less energy (released)

• (so) less muscle contraction

• (so) less blood / oxygen / glucose around the body (from heart)
or slower flow of blood / oxygen / glucose to body (from heart)
• less carbon dioxide removed from body (muscle / tissue / cells)
• (resulting in) breathlessness
• (resulting in) tiredness
• (anaerobic respiration causes) production of lactic acid
• (build-up of lactic acid) causes muscle fatigue / pain or chest
pain

For Level 3, students must explain the effect of reduced oxygen /

glucose on respiration or energy release and its consequence

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AO /
Question Answers Extra information Mark
Spec Ref.
02.9 any one pair from: mark as a pair AO1
4.2.2.4
• (insert) stent(s) allow description 1

(to) open (coronary) artery ignore unblock (coronary) artery 1

• (prescribe) statins (1)

(to) reduce (blood) allow to slow down the rate of

cholesterol (1) fatty material deposit

• heart (and lung) transplant (1)

(to) replace the diseased

heart with a healthy heart (1)

• use an artificial heart (1)

(to) keep the patient alive allow (artificial heart)

while waiting for a transplant pumps blood around the
(1) body in place of the heart

• (artery / heart) bypass (1) allow description

(to) divert blood around the

blockage (1)

Total Question 2 19

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Question 3

AO /
Question Answers Extra information Mark
Spec Ref.
03.1 (bacteria) release / produce allow (bacteria) release / 1 AO1
toxins produce poisons 4.3.1.3
4.3.1.1
ignore toxins unqualified

AO /
Question Answers Mark
Spec Ref.
03.2 Level 2: Relevant points (reasons / causes) are identified, given in 3-4 AO2
detail and logically linked to form a clear account.

Level 1: Relevant points (reasons / causes) are identified, and 1-2 AO1
there are attempts at logical linking. The resulting account is not
fully clear.
4.3.1.3
No relevant content 0 4.3.1.7

Indicative content:
Vaccination of animal
• (animal’s) white blood cells / lymphocytes produce antibodies
(against Salmonella / vaccine / antigens)
• antibodies are specific / complementary / correct to Salmonella
/ antigens
• (specific) antibodies bind to Salmonella / antigens

Secondary response in animal

• if infected (specific) antibodies are produced quickly or in large
numbers
• (so) white blood cells or antibodies would kill (live) Salmonella
• (so) fewer / no bacteria / pathogens / Salmonella in animals or
in animal products (meat / milk / eggs)

Prevention of food poisoning in humans

• (so) fewer / no bacteria / pathogens / Salmonella eaten or in
(named) food
• (so) number of bacteria never reaches a high enough level for
infection to develop
• (so) fewer toxins produced (in humans).

For Level 2 students must link immune response in animals to

prevention of an outbreak in humans.

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
03.3 any two from: allow alternative descriptions of 2 AO1
sterilising equipment such as 4.1.1.6
UV light RPA2
ignore clean / wash
surfaces / hands / equipment
• disinfect hands / work
surface

• sterilise Petri dish or culture allow sterilise agar (before use)

medium (before use)
ignore sterilise equipment
• pass inoculating loop /
forceps through a flame
(before use)

• work near a flame

or
work in a fume cupboard

• tilt lid (of Petri dish) when allow example of other method
placing discs on agar (to to minimise contact with air /
minimise contact with air / breath
breath)

• secure lid of Petri dish with

adhesive tape

ignore store dish upside-down

AO /
Question Answers Extra information Mark
Spec Ref.
03.4 (37 °C) AO2
4.1.1.6
37 °C is human / body 1
4.3.1.3
temperature
RPA2
Salmonella / bacteria grows best allow (so) bacteria grow best / 1
/ better at 37 °C better at human body
temperature
(25 °C)
25 °C reduces / prevents the allow because it is too low for 1
growth of bacteria that are growth of human pathogens
harmful to humans / students

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
03.5 (acts as a) control allow for comparison 1 AO2
4.1.1.6
allow to show that the results
RPA2
are not due to the paper disc
allow to show that the results
are due to the antibiotic
ignore to show the effect /
effectiveness of the antibiotic
do not accept as a control
variable

AO /
Question Answers Extra information Mark
Spec Ref.
03.6 (they) killed the most bacteria allow prevented most bacteria 1 AO2
growing / replicating 4.1.1.6
RPA2
allow largest zone of inhibition
(of bacteria)
ignore largest clear area
unqualified
ignore antibiotic B killed the
most bacteria

AO /
Question Answers Extra information Mark
Spec Ref.
03.7 measure the diameter / radius of allow measure the diameter / 1 AO3
each clear area radius of each region where the 4.1.1.6
bacteria are killed RPA2
or
calculate / measure the area of allow calculate the area of each
each clear area region where the bacteria are
killed

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AO /
Question Answers Extra information Mark
Spec Ref.
03.8 bacteria must be resistant (to do not accept bacteria must be 1 AO3
antibiotic B) immune 4.3.1.8

AO /
Question Answers Extra information Mark
Spec Ref.
03.9 water enters the (bacterial) cell 1 AO2
4.3.1.8
(water enters) by osmosis allow (water enters) by diffusion 1
4.1.3.2
through a partially / selectively /
4.1.1.1
semi permeable membrane
do not accept if description of
concentrations is incorrect

(so) damaged / incomplete / no allow (so remaining) cell 1

cell wall cannot withstand membrane cannot stretch
pressure (of water) further

Total Question 3 17

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Question 4

AO /
Question Answers Extra information Mark
Spec Ref.
04.1 any two from: mark as pairs 4 AO1
4.4.2.1
• (effect) muscle fatigue or allow muscle cramp
4.4.2.2
oxygen debt occurs (1) ignore fatigue / cramp
unqualified
(reason) caused by (build-up
of) lactic acid (1)

• (effect) (continued) heavy /

deep / fast breathing (1)

(reason) to provide the allow to repay the oxygen debt

oxygen needed to break down
(built-up) lactic acid (1)

• (effect) (continued) increased

heart rate (1)

(reason) to provide the allow to repay the oxygen debt

oxygen needed to break down
(built-up) lactic acid (1)

• (effect) fewer / weaker muscle

contractions (1)

(reason) (because) less do not accept energy being

energy is released / available produced / made / created
(1)

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AO /
Question Answers Mark
Spec Ref.
04.2 Level 3: The method would lead to the production of a valid 5-6 AO3
outcome. The key steps are identified and logically sequenced. 4.4.2.2

Level 2: The method would not necessarily lead to a valid 3-4

outcome. Most steps are identified, but the method is not fully
logically sequenced.

Level 1: The method would not lead to a valid outcome. Some 1-2
relevant steps are identified, but links are not made clear.

No relevant content. 0

Indicative content
• test a group of athletes
• use at least two different types / intensities of exercise
• get each athlete to do all exercises or have a large (≥30) group
doing each exercise

• record heart rate for each athlete before and after exercise or
calculate increase in heart rate for each athlete after exercise
• calculate the mean increase in heart rates for each type / intensity
of exercise
• compare mean increase in heart rates for each type / intensity of
exercise

• control variables:
o same (biological) sex or mix of sexes
o same level of activity / exercise
o same age
o same caffeine / drug / medicine intake
o same length of time for exercise
o no health issues / illnesses
o return to resting heart rate before each exercise

AO /
Question Answers Extra information Mark
Spec Ref.
04.3 (athlete is) faster / stronger allow description of improved 1 AO2
performance 4.4.2.1
4.4.2.2
allow reference to increased
stamina / endurance
(because more muscle mass so) 1
more / stronger muscle
contractions

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AO /
Question Answers Extra information Mark
Spec Ref.
04.4 hybridoma 1 AO1
4.3.2.1

AO /
Question Answers Extra information Mark
Spec Ref.
04.5 any three from: 3 AO1
4.3.2.1
• (cell) is cloned ignore name of cell

• many (identical) cells are allow many clones are produced

produced

• all the cells make the same

antibody

• the antibody is (collected and)

purified

AO /
Question Answers Extra information Mark
Spec Ref.
04.6 a monoclonal antibody only binds 1 AO2
to the anabolic steroid 4.3.2.1

AO /
Question Answers Extra information Mark
Spec Ref.
04.7 to show that the test is working allow to prevent a false negative 1 AO3
(result) 4.3.2.1
4.3.2.2
ignore to show there are free /
remaining monoclonal
antibodies

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AO /
Question Answers Extra information Mark
Spec Ref.
04.8 evidence AO3
no blue / visible dye (in control allow no line(s) (in control area) 1 4.3.2.1
area) allow no colour change (in 4.3.2.2
control area)
reason
(because) no (free) monoclonal allow the (free) monoclonal 1
antibodies bound to control area antibodies did not move up the
test strip
allow urine did not move up the
or
test strip

(because) there were no (free)

monoclonal antibodies on the
end of the (test) strip

AO /
Question Answers Extra information Mark
Spec Ref.
04.9 D 1 AO3
4.3.2.1
4.3.2.2

Total Question 4 21

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Question 5

AO /
Question Answers Extra information Mark
Spec Ref.
05.1 vector 1 AO1
4.3.1.5

AO /
Question Answers Extra information Mark
Spec Ref.
05.2 any three from: allow converse for prokaryotic 3 AO2
cells 4.1.1.1
allow eukaryotic for protist 4.3.1.5

• protist / it has mitochondria

if neither mark awarded,

allow 1 mark for protist has
• protist / it has (a) nucleus
membrane-bound
or protist DNA / genetic
structures
material is not free in the
ignore genetic information
cytoplasm

• protist / it does not have a ignore genetic information

single loop of DNA / genetic
material

• protist / it does not have

plasmids

• protist / it does not have a cell do not accept eukaryotic cell

wall does not have a cell wall

allow protist / it does not have a

slime capsule
ignore cilia / flagellae /
ribosomes
ignore size / shape

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AO /
Question Answers Extra information Mark
Spec Ref.
05.3 less oxygen carried (in blood) allow less oxygen carried (to 1 AO2
cells) 4.4.2.3
4.4.2.1
ignore reference to number of
4.2.2.3
red blood cells unqualified
do not accept no oxygen carried

less energy released from do not accept energy produced 1

respiration / made / created

AO /
Question Answers Mark
Spec Ref.
05.4 any three pairs from: 3 AO1
4.6.1.1
Sexual reproduction Asexual reproduction 4.1.2.2

involves two parents involves one parent

involves gametes joining / involves no (fusion of) gametes

fusing
or involves fertilisation or does not involve fertilisation

there is mixing of genetic there is no mixing of genetic

material / information material / information

or there is genetic variation or there is no genetic variation

or offspring are genetically or offspring are genetically

different identical

ignore reference to clones

involves (only) meiosis involves mitosis

or does not involve meiosis

more energy required less energy required

slower faster

if no other mark awarded allow 1 mark for asexual reproduction

produces many offspring
pairs of answers can be in any order

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AO /
Question Answers Extra information Mark
Spec Ref.
05.5 (no bases so) DNA replication allow copying / duplicating / 1 AO2
cannot occur doubling for replication 4.1.2.2
ignore cannot make DNA
unqualified

AO /
Question Answers Extra information Mark
Spec Ref.
05.6 (after DNA replication) one set allow one (member) of each pair 1 AO1
of chromosomes is pulled to of chromosomes is pulled to 4.1.2.2
each end of the cell each end of the cell

ignore (half the) chromosomes

are pulled to each end of the cell

nucleus divides allow two (new) nuclei form 1

cytoplasm or cell membrane allow cytokinesis 1

divides to form two cells

AO /
Question Answers Extra information Mark
Spec Ref.
05.7 having disorder S reduces allow having disorder S reduces 1 AO3
incidence / percentage of chance of getting malaria 4.2.2.5
malaria 4.3.1.5
allow having disorder S protects
against malaria

as age increases a lower allow protection against malaria 1

percentage of children with increases with (increasing) age
disorder S get malaria until age until age 10, then it decreases
10, then the percentage
increases

Total Question 5 15

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

Question 6

AO /
Question Answers Extra information Mark
Spec Ref.
06.1 (lhs) H2O + CO2 in either order 1 AO1
4.4.1.1
and
(rhs) O2

AO /
Question Answers Extra information Mark
Spec Ref.
06.2 from 0 to 5 000 lux 1 AO3
4.4.1.2

AO /
Question Answers Extra information Mark
Spec Ref.
06.3 any one from: 1 AO2
• use (different) coloured 4.4.1.2
bulb(s) / LED(s) RPA6

• use (different) coloured

filter(s) in front of lamp

• put (different) coloured allow named transparent

transparent material(s) over material(s)
lamp / beaker

AO /
Question Answers Extra information Mark
Spec Ref.
06.4 independent AO2
allow wavelength of light 4.4.1.1
colour of light 1
4.4.1.2
ignore colour of filter / bulb /
RPA6
lamp
dependent
time (taken for 10 leaf discs to 1
reach the surface of the
solution)

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
06.5 any one from: allow leaf for disc throughout 1 AO2
4.4.1.1
• so that discs would sink (to allow so the discs do not float
4.4.1.2
the bottom of the beaker)
RPA6

• so any gas (that makes the

discs rise) is from
photosynthesis

• air is a gas so any left in discs ignore reference to carbon

would add to the oxygen dioxide
produced by photosynthesis
allow as a control variable

AO /
Question Answers Extra information Mark
Spec Ref.
06.6 (sodium hydrogencarbonate) ignore (sodium 1 AO2
provides / releases carbon hydrogencarbonate) contains 4.4.1.1
dioxide carbon dioxide 4.4.1.2
ignore provides water RPA6
(carbon dioxide is used) for 1
photosynthesis

AO /
Question Answers Extra information Mark
Spec Ref.
06.7 oxygen was produced in 1 AO1
photosynthesis

oxygen / gas is trapped in / allow bubbles are trapped in / 1 AO2

around disc / leaf around the disc / leaf 4.4.1.1
allow oxygen / gas (makes leaf 4.4.1.2
discs) less dense than solution / RPA6
water
allow the oxygen / gas under the
disc / leaf pushes the disc / leaf
up

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MARK SCHEME – GCSE BIOLOGY – 8461/1H – JUNE 2023

AO /
Question Answers Extra information Mark
Spec Ref.
06.8 to absorb / use many / more allow to increase the rate of 1 AO2
colours / wavelengths of light photosynthesis 4.4.1.1
4.4.1.2
ignore to absorb as much light
as possible
do not accept to absorb all
colours / wavelengths of light

AO /
Question Answers Extra information Mark
Spec Ref.
06.9 chlorophyll absorbs most or a 1 AO3
lot of blue light

if neither mark awarded allow

1 mark for chlorophyll
absorbs more blue light (than
green light)

chlorophyll absorbs least or very allow chlorophyll reflects 1 AO3

little or not much green light most of the green light

(so) discs in blue light took the 1 AO2

least time to rise (to surface)
because they photosynthesised
faster / more
or
(so) discs in green light took the
most time to rise (to surface)
because they photosynthesised
slower / less

use of data (from Figure 10 and 1 AO2

Table 6) eg approximately 80% 4.4.1.1
of blue light absorbed 4.4.1.2

Total Question 6 15

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