Mark Scheme
Sample Assessment Material 2018
Pearson Edexcel International GCSE
In Biology (4BI1) Paper 1B
Pearson Edexcel International GCSE
in Science Double Award (4SD0) Paper 1B
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Sample Assessment Material 2018
All the material in this publication is copyright
© Pearson Education Ltd 2018
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.
Subject specific marking guidance
Symbols, terms used in the mark scheme

Round brackets ( ): words inside round brackets are to aid understanding of the
marking point but are not required to award the point

Curly brackets { }: indicate the beginning and end of a list of alternatives
(separated by obliques), where necessary, to avoid confusion

Oblique /: words or phrases separated by an oblique are alternatives to each
other and either answer should receive full credit.

ecf: indicates error carried forward which means that a wrong answer given in an
early part of a question is used correctly to a later part of a question.
You will not see ‘owtte’ (or words to that effect). Alternative correct wording should be
credited in every answer unless the mark scheme has specified specific.
The Additional Guidance column is used for extra guidance to clarify any points in the
mark scheme. It may be used to indicate:

what will not be accepted for that marking point in which case the phrase ‘do not
accept’ will be alongside the relevant marking point

it might have examples of possible acceptable answers which will be adjacent to
that marking point
Question
Number
1(a)(i)
Answer
Mark
C
1
Question
Number
1(a)(ii)
Answer
Mark
C
1
Question
Number
1(b)(i)
Answer
contraction of ventricles
right atrium
Additional guidance
Counting

Mark
2
6 peaks in 5.5s (1)
Multiplication

Question
Number
1(b)(ii)
6 ÷ 5.5 x 60 = 65 (1)
Award full marks for
correct numerical
answer without working
Answer
Mark
An explanation that makes reference to the following points:
2

more peaks / increased heart rate (1)

adrenaline (1)
Total for Question 1 = 6 marks
Question
Number
2(a)
Question
Number
2(b)(i)
Question
Number
2(b)(ii)
Answer
Mark
An answer that makes reference to two the following points:
2

thin (1)

large surface area (1)

rich blood supply (1)
Answer
Mark
An answer that makes reference to five of the following
points:
5

reduce population (1)

increase in oxygen consumption / demand (1)

reduction in available oxygen (1)

respiration affected (1)

bacteria grow (1)

death of fish (1)

migration (1)

only one fish used so results not reliable (1)
Answer

(water) temperature
Mark
1
Question
Number
2(b)(iii)
Answer
Mark
An explanation that makes reference to two of following
points:
2

fish killed (1)

enzymes denatured / eq (1)

less oxygen dissolved in water (1)

unethical / cruel / unnecessary (1)

range used is sufficient to show trend (1)
Total for Question 2 = 10 marks
Question
Number
3 (a)
Answer
Mark
1

spinal cord
Question
Number
3(b)(i)
Answer
Mark
B
1
Question
Number
3(b)(ii)
Answer
Mark
An explanation that makes reference to four of the following
points:
4
1.40 mm per s

person P (may) not be brain damaged because pupil
diameter decreased (1)

person Q has brain damage because pupil diameter did
not decrease (1)

person Q brain damage may be limited to part that
controls eye / vision (1)

damage could be to retina (1)

damage could be to optic nerve / sensory nerve (1)

damage could be to motor nerve (1)

radial muscles relax contract / circular muscles
contract in person P (1)
Total for Question 3 = 6 marks
Question
Number
4(a)
Question
Number
4(b)
Answer
Mark
An answer that makes reference to the following points:
6
S
scale linear and half grid (1)
L
lines clear and straight (1)
A
x axis is independent variable (1)
A
axes labelled with units (1)
P
points correctly plotted (1)
K
key provided (1)
Answer
Mark
An answer that makes reference to six of the following
points:
6
Argument for biological control being better:

ref to data / numbers are lower with biological control
(1)

biological control is specific / only kills whitefly (1)

no need to reapply (1)

pesticide fails to kill mutant / resistant whitefly (1)
Argument against biological control being better:

ref to data / biological control takes longer to reduce
whitefly (1)

wasps may escape and kill other species (1)

only one glasshouse used / data not reliable / no idea
about the size of each glasshouse (1)

no idea about control of abiotic factors (1)

no idea about species / age / size of plant (1)
Total for Question 4 = 12 marks
Question
Number
5(a)(i)
Answer
Mark
A
1
Question
Number
5(a)(ii)
Answer
one of them
Additional guidance
Multiplication
Mark
2
5.4 million x 1000 (1)
Expression
= 5400 million / 5.4 x 109 /
5 400 000 000 (1)
Question
Number
5(b)(i)
Answer
Award full marks for correct
numerical answer without
working
Additional guidance
Subtraction
Mark
2
25 – 15 = 10 (1)
Division and multiplication
10 ÷ 25 x 100 = 40 (1)
Question
Number
5(b)(ii)
Award full marks for correct
numerical answer without
working
Answer
Mark
An explanation that makes reference to four of the following
points:
4

less oxygen absorbed in lungs (1)

less oxygen transport to muscles (1)

less aerobic respiration (1)

less energy / ATP (1)

more lactic acid / anaerobic respiration (1)
Total for Question 5 = 9 marks
Question
Number
6(a)
Question
Number
6(b)
Answer
Mark
An explanation that makes reference to four of the following
points:
4

mutation causes variation (1)

those with flap of skin survive (1)

less energy used in finding food (1)

can cover greater distances to find more food (1)

easier to avoid predators (1)

reproduce and pass on allele for flap of skin (1)
Answer
Mark
A description that makes reference to four of the following
points:
5

oxygen (1)

glucose (1)

respiration / energy / ATP (1)

amino acids for protein (1)

diffusion (1)

remove carbon dioxide / urea (1)
Question
Number
6(c)
Answer
Mark
An explanation that makes reference to three of the following
points:
3

meiosis (1)

sperm/eggs have half the number of chromosomes (1)

sperm may contain X or Y chromosomes (1)

independent assortment / different combination of
chromosomes from each parent (1)

random fertilisation (1)

mutation (1)
Total for Question 6 = 12 marks
Question
Number
7 (a)
Question
Number
7 (b)(i)
Question
Number
7(b)(ii)
Answer
Additional
guidance
An answer that makes reference to the
following points:
4

measure oxygen produced /
CO2 used / starch produced (1)
ALLOW glucose

by counting bubbles /
use measuring cylinder / hydrogen
carbonate / iodine (1)
ALLOW
Benedict’s

stated time period (1)

control of abiotic variable (1)
Answer
Additional
guidance
A description that makes reference to the
following points:

both show peaks at blue and red (1)

both show trough in green / yellow (1)
Mark
Mark
2
Answer
Mark
An explanation that makes reference to the following points:
3

chlorophylls absorb different wavelength / colour of light
(1)

green light / 500 to 600 not absorbed / reflected so no
effect on photosynthesis (1)

blue / red light is absorbed so is effective at increasing
photosynthesis (1)
Question
Number
7(c)(i)
Answer
Mark
C light energy is converted to chemical energy
1
Question
Number
7(c)(ii)
Answer
Mark
B increase in the availability of carbon dioxide
1
Total for Question 7 = 11 marks
Question
Number
8(a)
Question
Number
8 (b)
Answer
Mark
2

A stigma

B anther
Answer
An answer that makes reference to four of
the following points:

Flower 1 is insect pollinated / Flower 2
is wind pollinated (1)

as Flower 1 has large petals / Flower 2
has no / small petals (1)

as Flower 1 is larger / Flower 2 is
smaller (1)

as Flower 2 has exposed / feathery
stigma / Flower 1 has enclosed stigma
(1)

as Flower 2 has exposed anthers /
hinged filaments / Flower 1 has
enclosed anthers (1)
Additional
guidance
Mark
4
Question
Number
8 (c)
Answer
Additional
guidance
An answer that that makes reference to six of
the following points:

C use range of soil pH (1)

O use genetically identical flowers of
same species (1)

R use many flowers in each soil pH (1)

M1 record colour of flower using chart/
extract pigment (1)

M2 grow plants for stated time (1)

S1 use same compost / same minerals
/ same water (1)

S2 same light intensity / same
temperature / same CO2 available (1)
Mark
6
To gain full
credit full
sentences and
detail must be
included
Total for Question 8 = 12 marks
Question
Number
9(a)
Answer
Question
Number
9 (b)
Answer
Question
Number
9 (c)

Mark
AIDS / Ebola / measles / tobacco mosaic / eq;
Additional
guidance
An answer that makes reference to three of
the following points:

viruses cannot divide / reproduce
without host cell (1)

viruses cannot respire (1)

viruses cannot make proteins (1)

viruses do not feed (1)

viruses do not grow (1)

viruses do not excrete (1)
Answer
An explanation that makes reference to four
of the following points:

viruses have antigens on their surface
(1)

white blood cells involved (1)

phagocytes engulf viruses (1)

lymphocytes produce antibodies (1)

antibodies are virus specific (1)
1
Mark
3
Additional
guidance
Mark
4
Question
Number
9 (d)
Question
Number
9(e)
Answer
Additional
guidance
An explanation that makes reference to four
of the following points:

most bacteria killed by antibiotic (1)

population number falls (1)

only resistant forms survive (1)

no competition with non-resistant
strains (1)

reproduce and pass on allele for
resistance (1)

most bacteria are now resistant (1)
Answer
Mark
4
Additional
guidance
Mark
2

26 = 64

500 x 64 = 32 000
Award full
marks for
correct
numerical
answer without
working
Total for Question 9 = 14 marks
Question
Number
10 (a)
Answer
Mark
5
Letter
A
B
C
D
E
F
Question
Number
10(b)(i)
Name of process
fossilisation
combustion (1)
respiration (1)
photosynthesis (1)
feeding (1)
death (1)
Answer


measured size = 4.3 cm
divided by 10 = 0.43 cm
Additional guidance
Mark
ALLOW range from 4.2 4.4 cm
2
Award full marks for
correct numerical answer
without working
Size of woodlouse will
depend upon how paper
printing is set up, centres
will need to measure this
on the hard copy they use.
Question
Number
10(b)(ii)
Answer
Mark
A
1
Question
Number
10(c)(i)
Answer
Mark
B
1
Question
Number
10 (c) (ii)
Answer
animals
fungi
An answer that makes reference to two of
the following points:

cellulose digested to glucose (1)

glucose absorbed (1)

gain (more) energy / respiration (1)
Additional
guidance
Mark
2
Question
Number
10 (c) (iii)
Answer
Additional
guidance
An answer that makes reference to one of
the following points:

bacteria get shelter (1)

bacteria get warmth / eq (1)

bacteria get food (1)
Mark
1
Total for Question 10 = 12 marks
Question
Number
11 (a)
Question
Number
11(b)(i)
Question
Number
11 (b)(ii)
Answer
Additional
guidance
A description that includes the following
points:

site of respiration (1)

release energy / form ATP (1)
Answer
Mark
2
Additional
guidance
Mark
2

1.4 divided by 100 x 20 (1)

x 1000 = 280 g (1)
Award full
marks for
correct
numerical
answer without
working
Answer
Additional
guidance
An explanation that includes the following
points:

sperm need energy / ATP
to swim to egg (1)

muscle cells need energy / ATP
for contraction (1)
Mark
2
Total for Question 11 = 6 marks
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