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COMBINED SCIENCE A

OCR 2024
GCSE Combined Science A
(Gateway Science)
J250/08 Biology (Higher Tier)
With Marking Scheme Merged

Oxford Cambridge and RSA

Friday 7 June 2024 – Afternoon
GCSE (9–1) Combined Science A
(Gateway Science)
J250/08 Biology (Higher Tier)
Time allowed: 1 hour 10 minutes

H

You must have:
• a ruler (cm/mm)
You can use:
• a scientific or graphical calculator
• an HB pencil

*

J

2

5

0

0

8

*

Please write clearly in black ink
...

Centre number

Candidate number

First name(s)
Last name
INSTRUCTIONS
• Use black ink
...

• Write your answer to each question in the space provided
...
The question numbers must be clearly shown
...

• Where appropriate, your answer should be supported with working
...

INFORMATION
• The total mark for this paper is 60
...

• Quality of extended response will be assessed in questions marked with an asterisk (*)
...

ADVICE
• Read each question carefully before you start your answer
...

Write your answer to each question in the box provided
...

Which change would increase biodiversity?
A Adding chemical fertilisers to a grass lawn B
Cutting a grass lawn more often than usual
C Removing a grass lawn area and putting down paving stones D
Replacing a grass lawn area with a wild flower meadow
Your answer

2

[1]

Which row is a correct comparison of meiosis and mitosis?
Involves cell
division

Halves the number
of chromosomes

Requires DNA
replication

A

both

meiosis only

both

B

both

both

both

C

meiosis only

both

mitosis only

D

mitosis only

meiosis only

mitosis only

Your answer

© OCR 2024

[1]

3
3

Which statement describes a difference between red blood cells and white blood cells?
A Red blood cells contain enzymes
...
C
White blood cells contain proteins
...


Your answer
4

[1]

Which disease may develop due to an interaction with HPV?
A AIDS
B Cervical cancer C
Tuberculosis D Type
2 diabetes

Your answer
5

[1]

Why does a plant scientist use antibodies specific to a type of antigen?
A To develop new plants using selective breeding
B To find new species of plants growing around the world
C To identify communicable diseases in plants
D To study the evolution of plants

Your answer

© OCR 2024

[1]

Turn over

4
6

Which row shows the correct order of some processes in the water cycle?
A

Condensation

evaporation

precipitation

condensation

B

Condensation

precipitation

evaporation

condensation

C

Precipitation

condensation

evaporation

precipitation

D

Precipitation

evaporation

condensation

evaporation

Your answer
7

[1]

The diagram shows a phylogenetic tree for a group of related
animals
...


B

Animal X is a common ancestor to all the hyenas
...


D

The closest relation to the striped hyena is the spotted hyena
...

Pathogen growing
on agar plate
Clear zone where
pathogen does not
grow

Paper disc
containing
new drug

The area of the clear zone is used to indicate the effectiveness of the drug
...
4 cm
...
14
A

2
37
...
36 mm

C

2
452
...
64 mm

2

Your answer

9

[1]

Which row shows how a high cholesterol diet is linked to cardiovascular disease?
Coronary vessel blocked
by cholesterol

Gas unable to be transported
to cardiac muscle, damaging
the heart

A

artery

carbon dioxide

B

artery

oxygen

C

vein

carbon dioxide

D

vein

oxygen

Your answer

© OCR 2024

[1]

Turn over

6
10

To function correctly, the brain needs to make a chemical called dopamine
...

Embryonic stem cells might be used to treat Parkinson’s disease
...

B The embryonic stem cells may not produce the correct type of dopamine
...
D
The embryonic stem cells will not have the same genome as the patient
...

(a) In an investigation, scientists estimated the population of flying insects in a forest
...

The mass of insects collected each month is then recorded
...


The table shows their results
...

Both years should be included on the same grid
...


May

June

July
Month

Aug

Sept

[4]
© OCR 2024

9
(ii) What two conclusions can be made about the mass of flying insects in 1995 compared to 2015?
1
...

2
...

[2]
(iii) How can the scientists’ method be developed to investigate biodiversity in the
forest? Tick (3) one box
...

Record the number of different species found in the nets
...

Use their data to calculate mean mass for each year
...

The scientists trap insects using a pitfall trap
...

For each estimate they use this method:
•
•
•
•

Place pitfall traps in different areas of the forest
...

Mark the insects
...


A week later they trap a second sample of insects
...

State one other precaution that they should take when deciding how to mark the insects
...


...
This table shows the results
of this investigation
...

Use the formula to estimate the population size of insects in 2015
...


Estimated population of insects =
...

The population of insects living on the forest ground increased between 1995 and 2015
...

True

False

Both investigations came to the same conclusion about
changes in insect population
...

Only one investigation shows how the insect population
changes with each month
...

[2]

© OCR 2024

11
BLANK PAGE

PLEASE DO NOT WRITE ON THIS PAGE

© OCR 2024

Turn over

12
12 Genetic material is required for inheritance in eukaryotic and prokaryotic cells
...


...


...
[2]

(b) Peas develop inside pods
...
The allele for green is dominant over the allele for
yellow
...

Complete the table
...

homozygous dominant

Gg

...

[2]

© OCR 2024

13
(ii) A gardener crosses a plant that has green pods with a plant that has yellow
pods
...

The result is 15 new plants with green pods and 3 plants with yellow pods
...

Use letters G and g for the alleles
...

If the green plant does not have a homozygous genotype:
yellow pods

green pods

Offspring ratio
...

Suggest why this does not match either of the offspring ratios
...


...


(a) Describe how powdery mildew is spread from one plant to another
...


...
[2]

(b) Powdery mildew reduces the efficiency of chloroplasts
...


...


...


...

(i)

Complete the sentences about genetic engineering
...
enzyme
...
enzyme
...


...

[3]

(ii) Explain why the process of cutting the DNA is prevented by high
temperatures
...


...


...
[2]

(d) Powdery mildew can be controlled using chemicals
...

Suggest two reasons why
...


...


...

(a) Two students investigate the moisture content of different
soils
...

Place the soil samples in a warm oven to dry for 4 hours
...


The table shows their results
...
1

97
...
0

B

154
...
5

18
...
3

121
...


Calculate the percentage change in mass of soil sample C
...
Write your answer in the table
...

Why is the percentage change in mass greater for soil sample A?

...

•
•

Student Y used a similar method but left the soil in the oven for a different length of time
...


Explain why student Y found the moisture content of soil sample C to be higher than student X
...


...


...


...

The amount of microorganisms in the soil can also affect plant growth
...



...


...


...


...

They evolved from a much smaller pigeon that flew to the island
...

There were originally no predators or humans on Mauritius
...

Humans arrived on the island in 1598
...

The dodo became extinct by 1700
...


...


...


...


...


...


...
[6]

(b) Suggest one way scientists could find evidence that the pigeon and the dodo have a common
ancestor
...


...
You must write the question numbers clearly
in the margin
...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


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...
OCR qualifications include
AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills,
Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT,
business, languages, teaching/training, administration and secretarial skills
...
OCR is a not-for-profit organisation; any surplus made
is invested back into the establishment to help towards the development of qualifications and
support, which keep pace with the changing needs of today’s society
...
It shows the basis on which marks were awarded by examiners
...

All examiners are instructed that alternative correct answers and unexpected approaches
in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and
skills demonstrated
...

© OCR 2024

Oxford Cambridge and RSA Examinations

J250/08

Mark Scheme

June 2024

MARKING INSTRUCTIONS
PREPARATION FOR MARKING
RM ASSESSOR
1
...


2
...
These are available in RM A ssessor
...


Log-in to RM Assessor and mark the required number of practice responses (“scripts”) and the required number of standardisation
responses
...


Mark strictly to the mark scheme
...


Marks awarded must relate directly to the marking criteria
...


The schedule of dates is very important
...
If you experience problems, you must contact your Team Leader (Supervisor) without delay
...


If you are in any doubt about applying the mark scheme, consult your Team Leader by telephone, email or via the RM Assessor messaging
system
...


Mark Scheme

June 2024

Crossed Out Responses
Where a candidate has crossed out a response and provided a clear alternative then the crossed out response is not marked
...

Rubric Error Responses – Optional Questions
Where candidates have a choice of question across a whole paper or a whole section and have provided more answers than requir ed, then
all responses are marked and the highest mark allowable within the rubric is given
...
(The underlying assumption is that the candidate has penalised themselves
by attempting more questions than necessary in the time allowed
...
When
a question requires candidates to select more than one option/multiple options, then local marking arrangements need to ensure consistency
of approach
...

Short Answer Questions (requiring only a list by way of a response, usually worth only one mark per response)
Where candidates are required to provide a set number of short answer responses then only the set number of responses should be marked
...
The remaining responses should not then be marked
...
(The underlying assumption is that the candidate
is attempting to hedge their bets and therefore getting undue benefit rather than engaging with the question and giving the m ost
relevant/correct responses
...
)
Longer Answer Questions (requiring a developed response)
Where candidates have provided two (or more) responses to a medium or high tariff question which only required a single (deve loped) response
and not crossed out the first response, then only the first response should be marked
...

6
...
If the
candidate has continued an answer there, then add the annotation SEEN to confirm that the work has been seen
...


Award No Response (NR) if:
•

there is nothing written in the answer space

Award Zero ‘0’ if:
• anything is written in the answer space and is not worthy of credit (this includes text and symbols)
...

8
...
Please refer to these
comments when checking your practice responses
...

If you have any questions or comments for your Team Leader, use the phone, the RM Assessor messaging system, or email
...


Assistant Examiners will send a brief report on the performance of candidates to their Team Leader (Supervisor) via email by the end of the
marking period
...
Constructive
criticism of the question paper/mark scheme is also appreciated
...


Mark Scheme

June 2024

For answers marked by levels of response:
Read through the whole answer from start to finish, using the Level descriptors to help you decide whether it is a strong or weak answer
...
Using a ‘best-fit’ approach based on the skills and science content evidenced
within the answer, first decide which set of level descriptors, Level 1, Level 2 or Level 3 , best describes the overall quality of the answer
...

The lower mark should be awarded where the level descriptor has been evidenced but aspects of the communication statement (in italics)
are missing
...

The communication statement determines the mark within a level
...


5

J250/08

11
...


Annotation

Meaning

/

alternative and acceptable answers for the same marking point



Separates marking points

DO NOT ALLOW

Answers which are not worthy of credit

IGNORE

Statements which are irrelevant

ALLOW

Answers that can be accepted

()

Words which are not essential to gain credit

__

Underlined words must be present in answer to score a mark

ECF

Error carried forward

AW

Alternative wording

ORA

Or reverse argument

7

J250/08
12
...
This mate rial includes:
•

the specification, especially the assessment objectives

•

the question paper

•

the mark scheme
...

You should ensure also that you are familiar with the administrative procedures related to the marking process
...
If you are examining for the first time, please read carefully Appendix 5 Introduction to Script Marking:
Notes for New Examiners
...
Your first point of contact is your Team Leader
...


AO1
...


AO1
...


AO2

Apply knowledge and understanding of scientific ideas and scientific enquiry, techniques and procedures
...
1

Apply knowledge and understanding of scientific ideas
...
2

Apply knowledge and understanding of scientific enquiry, techniques and procedures
...
1

Analyse information and ideas to interpret and evaluate, make judgements and draw conclusions and develop and improve
experimental procedures
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


9

J250/08

Mark Scheme

June 2024

For answers to Section A if an answer box is blank ALLOW correct indication of answer e
...
, circled or underlined
...
1

2

A

1

1
...
1

4

B

1

1
...
1

6

B

1

1
...
1

8

C

1

2
...
1

10

A

1

1
...
2 Place ticks and crosses on right hand side of
grid

2





Pattern across months is the same

2 x 3
...
g
...
Must refer to both years
ALLOW reference to comparisons in the patterns
of numbers/population of insects
11

J250/08

Mark Scheme

Question
Answer
(iii) Record the number of different species found in the nets

Marks
1



(b)

(i)

June 2024

Any one from:

1

AO
element
3
...
2

Idea that mark must not make it more visible to predators

ALLOW mark not visible to predators / doesn't
make it more likely they get eaten by predators /
do not use bright ink
DO NOT ALLOW so it is visible
BUT ALLOW only visible under UV light
IGNORE make sure it is marked in the same place

Idea that mark should not be toxic or poisonous (to the

ALLOW does not cause harm (to the insect /
predator)
IGNORE does not affect (the insect)
IGNORE not too much paint or ink / different
colours



insect)



ALLOW answers in terms of questions e
...

will it make it visible to predators?
will it harm the insect?
(ii)

First check the answer on the answer line
If answer = 1530 award 2 marks

2

2 x 2
...
figs)

(c)

False
False
True
True


2



12

2 x 3
...
1

Guidance

✓
ALLOW prokaryotic cells have plasmids / loop of
DNA/genetic material
ALLOW prokaryotic cells have (free) floating DNA/
have (free) floating genetic material
IGNORE plasma
ALLOW both made from DNA as an additional
marking point

(b)

(i)

Recessive

✓

Green and heterozygous

(ii)

2

✓

Both genetic crosses correct

2 x 2
...
1

yellow pods
g
g
green

G

Gg

Gg

pods

G

Gg

Gg

yellow pods
g

13

g

green

G

Gg

Gg

pods

g

gg

gg

J250/08

Mark Scheme

Question

Answer

June 2024

Marks

AO
element

Answer is dependent on first genetic cross
Homozygous genotype offspring ratio = 4 : 0 ✓

ALLOW all green / 1:0 / 18:0
ALLOW 0:1 / 0:18 / 0:4 unless colours incorrectly
stated
ALLOW ECF from their genetic cross
IGNORE percentages

Answer is dependent on second genetic cross
✓

ALLOW 2:2 / 9:9 / 50:50
ALLOW ECF from their genetic cross
IGNORE percentages

Not homozygous genotype offspring ratio = 1 : 1

(iii) Sample size too small

Guidance

✓
1

14

2
...
1

NOTE the idea of ‘less’ or ‘reduced’ must be seen
once in the answer to gain 3 marks

3

Reduces the rate of photosynthesis

✓

Photosynthesis produces (less) oxygen/glucose

Idea that glucose is needed for respiration

(i)



Ligase

2
...
1

ALLOW no glucose produced
ALLOW correct word or symbol equation for
photosynthesis
DO NOT ALLOW less carbon dioxide is produced

1
...
g
...
1
DO NOT ALLOW lipase
ALLOW marker gene
ALLOW idea of using antibiotics to see if they
affect bacteria, those unaffected contain the gene





15

J250/08

Mark Scheme

Question

(ii)

AO
Marks element

Answer

Any two from:
Enzyme denatures

June 2024

2

2 x 1
...
1
ALLOW ORA
ALLOW named pollinator
IGNORE reference to humans



Idea that chemicals may reduce food source for animals

ALLOW prevents bioaccumulation / description of

higher in food chain

bioaccumulation
IGNORE ideas about cost
IGNORE ideas that plants may develop resistance



16

J250/08

Mark Scheme

Question
Answer
14 (a) (i) First check the answer in table or answer space
If answer = 3
...
0 x 100
126
...
1

Guidance

ALLOW 121
...
3 x 100
126
...
3 -121
...
3



= 3
...
2



= 3
...
e
...
3
or 247
...
95882…
...
12
IGNORE % sign in the body of the table



1

3
...
1b

Assume answers refer to Y unless X stated

1

3
...
1



ALLOW description of breaking down
dead/organic matter / decay / rot
IGNORE soil microorganisms die and decompose
IGNORE nutrients

Return minerals/nitrogen/nitrogen compounds (to the
soil)

ALLOW recycle/provide minerals/nitrogen/nitrogen
compounds
ALLOW provides or returns to the soil named
mineral/nitrogen compound
IGNORE nutrients
DO NOT ALLOW provide energy for the plant



Minerals/nitrogen/nitrogen compounds needed to make



proteins / amino acids

Proteins are needed for growth



DO NOT ALLOW other named nutrients needed
for growth
ALLOW 2 marks for break down urea into
ammonia for MP1 and MP2
Additional marking point nitrogen fixing bacteria

(c)

Microorganisms are living and (soil) moisture is a nonliving/physical factor

1





19

1
...

Level 3 (5–6 marks)
Detailed explanation of evolution
AND
Detailed explanation of why they became extinct
There is a well-developed line of reasoning which is clear
and logically structured
...

Level 2 (3–4 marks)
Detailed explanation of evolution and an attempt at an
explanation of why they became extinct
OR
Detailed explanation of why they became extinct and an
attempt at explanation of evolution
OR
A reasonable explanation of evolution and a reasonable
explanation of why they became extinct
There is a line of reasoning presented with some
structure
...


AO
Marks element
6
3 x 2
...
2a

June 2024

Guidance
AO2
...
2a Analyse information and ideas to make
judgments about extinction of dodo
• humans introduced animals that ate the dodo
eggs/ are predators of the dodo / destroyed
forests
• animals/ humans destroyed nesting sites/
habitat
• dodo could not escape predators as could not
nest in / fly up to the trees
• eggs eaten so no offspring
• no offspring as dodo could not nest in trees to
protect their eggs

Level 1 (1–2 marks)
Attempts explanation of evolution
OR
Attempts explanation of why they became extinct
There is an attempt at a logical structure with a line of
reasoning
...


20

J250/08

Mark Scheme

Question

June 2024

AO
Marks element

Answer
0 marks
No response or no response worthy of credit
...
1

Guidance
• Idea that eggs were being destroyed faster /
overhunted than the dodos could reproduce
• animals introduced by humans out-competed
dodos for food
• not enough time for dodos to adapt to grow
bigger wings / escape predators / nest in trees
ALLOW comparing bone structure



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