PMT

Mark Scheme
(Results)

Summer 2019

Pearson Edexcel GCSE

In Biology (1BI0) Paper 1F
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Summer 2019
Publications Code 1BI0_1F_1906_MS
All the material in this publication is copyright
© Pearson Education Ltd 2019
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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.
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Mark schemes have been developed so that the rubrics of each mark scheme reflects the
characteristics of the skills within the AO being targeted and the requirements of the command
word. So for example the command word ‘Explain’ requires an identification of a point and then
reasoning/justification of the point.

Explain questions can be asked across all AOs. The distinction comes whether the identification is
via a judgment made to reach a conclusion, or, making a point through application of knowledge
to reason/justify the point made through application of understanding. It is the combination and
linkage of the marking points that is needed to gain full marks.

When marking questions with a ‘describe’ or ‘explain’ command word, the detailed marking
guidance below should be consulted to ensure consistency of marking.

Assessment Command Word

Objective

Strand Element Describe Explain

AO1 An answer that combines the An explanation that links

marking points to provide a logical identification of a point with
description reasoning/justification(s) as required

AO2 An answer that combines the An explanation that links

marking points to provide a logical identification of a point (by applying
description, showing application of knowledge) with
knowledge and understanding reasoning/justification (application
of understanding)

AO3 1a and An answer that combines points of

1b interpretation/evaluation to provide
a logical description

AO3 2a and An explanation that combines

2b identification via a judgment to
reach a conclusion via
justification/reasoning

AO3 3a An answer that combines the

marking points to provide a logical
description of the
plan/method/experiment

AO3 3b An explanation that combines

identifying an improvement of the
experimental procedure with a
linked justification/reasoning
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S.S Answer Mark

Question

1(a)(i) sexual (1)

AO1

Question Answer Mark

number

1(a)(ii) (1)
B there is variation in the offspring
AO1
1aii The only correct answer is B

A is not correct because the offspring are

different

C is not correct because fertilisation occurs

D is not correct because the offspring do not

grow faster

Question Answer Mark

number

1(b)(i) (1)

AO2
r r
Accept rR
R Rr Rr

R Rr Rr

Correct offspring (1)

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Question Answer Additional Mark

number guidance

1(b)(ii) accept correct (1)

100% (1)
percentage from
AO2
incorrect Punnett
square in 1bi.

Question Answer Mark

number

1(b)(iii) (1)
D Gregor Mendel
AO1
1biii The only correct answer is D

A is not correct because Charles Darwin did not discover the

basis of genetic inheritance

B is not correct because Alfred Wallace did not discover the

basis of genetic inheritance

C is not correct because Louis Leakey did not discover the basis
of genetic inheritance

Question Answer Additional guidance

Mark
number

1(c) Any two from:

(2)
• Inherit A from one accept inherit A from mother /
parent (1) father AO1(1)

• Inherit B from the accept inherit B from father /

other parent (1) mother
• (IA and IB) are
codominant (1)

(Total for Question 1 = 7 marks)

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Question Answer Additional Mark

number guidance

2(a)(i) (2)
An answer including:
AO1 1
• (the root tip) contains {meristem
/ dividing} cells (1) reject meiosis

• for growth (1)

Question Answer Additional Mark

number guidance

2(a)(ii) (2)
An answer combining:
accept adjust AO1 2
• switch the lamp on the mirror

• start with the lowest objective accept start

lens / look through the with x4 / x10
eyepiece lens (1)
objective lens
• use the (focusing) wheel to
obtain a clear image (1)

Question Answer Additional Mark

number guidance

2(a)(iii) accept dye / (1)

use a stain / named stain
iodine
AO3 3b

Question Answer Mark

number

2(b)(i) (1)
C anaphase
A
2bi The only correct answer is C
O
1

A is not correct because the chromosomes are arranged

differently in prophase

B is not correct because the chromosomes are arranged

differently in metaphase

D is not correct because the chromosomes are arranged

differently in telophase
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Question Answer Additional guidance M

number a
r
k

2(b)(ii) (
A description including:
3
)
• spindle (fibres) (1)
A
• are pulling the accept chromatids O
chromosomes (1) 1
1

• to either side of the cell /

poles (1)

(Total for Question 2 = 9 marks)

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Question Answer Mark

number

3(a)(i) (1)
C sexual intercourse
AO1 1
3ai The only correct answer is C

A is not correct because insect vectors do not transmit Chlamydia

B is not correct because Chlamydia is not transmitted by

sneezing

D is not correct because Chlamydia is not transmitted by

contaminated food

Question Answer Mark

number

3(a)(ii) (1)
A bacterium
AO1 1
3aii The only correct answer is A

B is not correct because Chlamydia is not caused by a fungus

C is not correct because Chlamydia is not caused by a protist

D is not correct because Chlamydia is not caused

by a virus

Question Answer Mark

number

3(b)(i) (2)
An answer that links the following:

• number of cases increases (1) AO3 1a b

• and then decreases (1)

• correct reference to data from graph (1)

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Question Answer Additional guidance Mark

number

3(b)(ii) (1)
graph reading 1 800 (1)
AO1 1

3(b)(iii) (2)
64 000 000 ÷ 100 000 = 640 (1) award full marks for
correct answer with no
(640 x 1 800 =) 1 152 000 working
(cases)
allow ecf from 2bii

(Total for Question 3 = 7 marks)

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Question Answer Additional

Mark
number guidance

4(a) An answer linking:

(2)
• waxy cuticle / (physical) barrier (1) accept waxy layer
/ waterproof AO1(1)
surface
• to prevent entry to pathogens (1)

Question Answer Mark

number

4(b)(i) A aseptic technique (1)

AO2(2)
4bi The only correct answer is A

B is not correct because the technique shown is not cloning

C is not correct because the technique shown is not genetic
engineering
D is not correct because the technique shown is not selective
breeding

Question Answer Additional Mark

number guidance

4(b)(ii) An answer that links the following: (2)

• Bunsen burner creates {a AO2(2)

convection current/uplift} (1)
• prevents microorganisms in the
air falling onto the agar plate /
contamination (1)

OR

• to sterilise the loop / spreader (1)

accept kill bacteria

• to prevent transfer of unwanted
microorganisms / contamination on the loop /
(1) spreader /metal
wire
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Question Answer Additional Guidance Mark

number

4(c)(i) substitution 2 marks for correct

(2)
3.14 x 12 x 12 (1) answer without any
working AO1(2)
accept π x 122 / 3.14 x
122 /
3.14 x 144

452.16 accept any answer

between 452 and
452.4

Question Answer Additional Mark

number Guidance

4(c)(ii) Any two from:

(2)
• species / type of bacteria (on
both plates) (1) AO1(2)
• volume of chemical (1)
accept strength
• concentration of chemical (1) of chemicals

• (incubation) temperature (1)

• (incubation) time (1)
• nutrient agar (1)
• size of filter disc (1)
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Question Answer
Additional Mark
number
guidance
4(d) An answer that links the following:
(2)
• kills insects /pests / pathogens (which
feed on the crops) (1) AO1(1)

• less damage to the crops / increased

crop yield (1)

• no need to use insecticides / pesticides

(1)
accept fungicides

(Total for Question 4 = 11 marks)

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Question C.S. Answer Additional Mark

number Question guidance

5(a)(i) 3(a)(i) (4)

An answer including:
expert
• reference to enzyme
activity (1) AO3 1a
b

accept a range
• (the enzyme activity)
of pH 5.6 to 6
increases from pH 5.8 to
for pH 5.8
pH 8 (1)

accept activity
• optimum (activity) at pH 8
peaks at pH 8
(1)

accept
• (enzyme activity) reference to
decreases between pH 8 range of pH
and pH 9.8 (1) 9.6 to 10 for
pH9.8

Question C.S. Answer Additional Mark

number Question guidance

5(a)(ii) 3(a)(ii) accept (pH) two (1)

(pH) 2
/ 2 pH
AO3
1a

Question Answer Mark

number

5(a)(iii) Two from: (2)

• conditions in the stomach are pH 2 / AO1

acidic / low pH (1)

• (The stomach secretes) hydrochloric acid (1)

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Question Answer Mark

number

5(b) (1)
B denatured
AO1 (1)
5b The only correct answer is B

A is not correct because the enzyme is not specific when it

changes shape

C is not correct because the enzyme is not digested when it

changes shape

D is not correct because the enzyme is not dead when it

changes shape

Question C.S. Answer Mark

number Question

5(c) 3(c) (1)

amino acids
AO1 1

(Total for Question 5 = 9 marks)

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Question Answer Additional Mark

number guidance

6(a)(i)
Any two from:
(2)
• this karyogram contains pairs of
chromosomes / 46 chromosomes accept diploid AO2
(1)

accept haploid
• gametes only have 23
chromosome / chromosomes are
not in pairs (1)

• because it has an X and a Y

chromosome (1)

Question Answer Additional guidance Mark

number

6(a)(ii) accept boy / man (1)

male
accept other valid responses AO3 2a 2b

Question Answer Additional Mark

number guidance

(2)

6(a)(iii) grad
X Y 1 mark for
gametes AO2

X XX XY 1 mark for
correct offspring
genotypes
X XX XY
allow ecf for
correct
genotypes in
Punnett square
from incorrect
male and female
gametes
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Question Answer Additional guidance Mark

number

6(a)(iv) 0.5 / 50% / ½ / 1 in 2 / accept 2/4 (1)

/ 2 in 4 AO2

50 : 50 is a ratio, not a
probability and should
score 0

Question Answer Additional guidance Mark

number

6(b)(i) acrosome Reject achromosome / (1)

chromosome / head
AO1 (1)

Question Answer Mark

number

6(b) (ii)
Any three from: (3)
• (middle section) contains mitochondria (1) AO2 1
• so has more mitochondria (in middle piece of
sperm B) (1)

• (sperm B can) release more energy / has a faster

rate of respiration (1)

• (sperm B) swims faster / greater distance (1)

(Total for Question 6 = 10 marks)

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Question Answer Additional guidance Mark

number

7(a) amylase (1) accept carbohydrase (1)

1.12 AO1

Question Answer Additional guidance Mark

number

7(b)(i) starch is present / iodine reacts accept starch hadn’t (1)

with starch (1) reacted / hadn’t been
1.12 AO1
broken down (by liquids
from mouth and
stomach)

Question Answer Additional guidance Mark

number

7(b)(ii) An answer linking three from: Accept reverse (3)

argument for both
A03 2a+2b
marking points in test
• in test tube 1 starch has tube two
been broken down (1)

• in test tube 2 starch has

not been broken down
(1) accept starch is still
present in tube 2

• because amylase is
present in the mouth / accept carbohydrase
no amylase in the
stomach (1)
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Question Indicative content Mark

number

7(c)* AO3

Using the equipment AO3

3a +
• add water to the boiling tube
AO2 2
• place food/named food on mounted needle
• take the starting temperature of the water
• ignite / burn the food (6)
• take the temperature of the water when the food stops
burning /record the highest temperature of the water
• repeat the test using the other food

AO2

Controlling variables

• mass of food measured with a balance

• volume of water measured with a measuring cylinder
• starting temperature of water measured with a
thermometer
• distance of food from boiling tube measured with a
ruler
• burning time measured with a stopwatch
• external temperature/draughts prevented by placing a
screen around the apparatus

Level Mark Descriptor

0 • No awardable content

Level 1 1-2 • The explanation attempts to link and apply knowledge and
understanding of scientific ideas, flawed or simplistic
connections made between elements in the context of the
question.
• Lines of reasoning are unsupported or unclear. (AO2)
Level 2 3-4 • The explanation is mostly supported through linkage and
application of knowledge and understanding of scientific
ideas, some logical connections made between elements
in the context of the question.
• Lines of reasoning mostly supported through the
application of relevant evidence. (AO2)
Level 3 5-6 • The explanation is supported throughout by linkage and
application of knowledge and understanding of scientific
ideas, logical connections made between elements in the
context of the question.
• Lines of reasoning are supported by sustained application
of relevant evidence. (AO2)
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Level Mark Additional Guidance General additional guidance

The detail and workability of the method drives the level. The information
about variables and how to control them determines the mark within the
level

0 No rewardable material.

Level 1 1–2 A simple plan including at least one aspect Possible candidate responses
of using the equipment (AO3)
Burn the food under the tube. Keep the mass of food the same.
A reference to at least one variable (AO2)

Level 2 3–4 A plan including more than one aspect of Possible candidate responses
using the equipment (AO3) Put water in the boiling tube. Stick food onto mounted needle and burn it
under the tube. Keep the mass of food and the volume of water the same.
A reference to two or more variables (AO2)
Stick the food on the mounted needle. Measure the temperature of the water
OR at the start, then burn the food. Measure the temperature of the water at the
end. Keep the mass of food the same by weighing it on a balance.
A reference to one variable and how it is
controlled (AO2)

Level 3 5–6 A detailed, workable plan including several Possible candidate responses
aspects of using the equipment (AO3)
Put water in the boiling tube and measure it’s temperature. Stick the food on
A reference to at least two variables and an the mounted needle, light it and hold it under the tube. When the food burns
explanation of how to control at least one out measure the temperature again. Keep the distance from the food to the
variable (AO2) tube the same by measuring it with a ruler. Repeat with the second food,
using the same volume of water that has been measured with a measuring
cylinder.
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Question Answer Mark

number

8(a)(i) (1)
A each pair of bases is joined by hydrogen bonds
AO1(1)
8ai The only correct answer is A

B is not correct because phosphate groups are not joined

by hydrogen bonds

C is not correct because nucleotides consist of a sugar, a

phosphor group and a base

D is not correct because bases are not joined to

phosphate molecules

Question Answer Additional Guidance Mark

number

8(a)(ii) An answer that combines points (2)

of interpretation/evaluation to
AO3(1a+1b)
provide a logical description:

• amount of C and G is
equal/amount of A and T is
equal
• A pairs with T and C pairs
with G
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S.S. number Answer Additional Guidance Mark

8(b)
award full marks for (2)
division correct answer with no AO2(1)
working
0.0062 ÷ 2 / 6.2 ÷ 2 (1)

OR

unit conversion

0.0031 x 1000 / 0.0062 x

1000 (1)

accept 6.2/ 0.0031 for 1

3.1 (picograms) mark with no working

Question Answer Additional Guidance Mark

number

8(c)(i) to precipitate the DNA accept so the DNA is AO1 (2)

visible / so the DNA is
(1)
not soluble (in ethanol)
/
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Question Answer Additional Guidance Mark

number

8(c)(ii) Any two from:

(2)
• mass of fruit (1) accept amount of fruit /
number of fruit cells A02 (2)
/size of fruit

ignore amount of buffer

• volume of buffer (1)

accept idea of
• crushing method /crushing
incubation time
time / crushed evenly (1)

ignore amount of
• volume of ethanol (1)
ethanol

• temperature (1)

• pH /same buffer solution (1)

accept fully filtered (1)

accept same
concentration of
ethanol (1)
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Question Answer Additional Guidance Mark

number

8(c)(iii) Any one from:

(1)

AAO2(2)
• to obtain more data (1)
• to identify anomalies (1)
• see if the results are {the
same / reliable/correct} (1)
• to calculate a
{mean/average} (1)

accept to be sure
their {results are
valid / conclusion is
valid} (1)

ignore
accuracy/precision
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Question Answer Additional Guidance Mark

number

8(d) Any three from:

AO1 1
• mitosis produces 2 cells and (3)
meiosis produces 4 cells (1)

• mitosis produces genetically accept offspring for

identical cells and meiosis cells
produces genetically different
cells (1)

• mitosis produces diploid cells

and meiosis produces haploid
cells (1)

• mitosis produces body cells

and meiosis produces
{gametes /sex cells} (1)

mitosis is involved in
asexual reproduction
and meiosis is
involved in sexual
reproduction (1)

(Total for question 8 = 12 marks)

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Question Answer Additional Mark

number Guidance

9(a) An explanation linking three of the AO2(1)

following:
(3)
• they are immune (to
Clostridium tetani) (1)
accept idea of
• because the vaccination inactive/dead
contained an antigen / bacteria in the
bacteria have antigens (1) vaccine

• memory lymphocytes (1)

• leading to the production of

antibodies (1)

• leading to a secondary
(immune) response (1)
accept bacteria killed
{faster/ quicker/
quickly}
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Question Answer Additional guidance Mark

number

9(b) An explanation linking four of the

AO2 1
following:
(4)

• people do not finish their course accept overuse /

(of Colistin) (1) repeated exposure
(to the antibiotic)

• natural selection /evolution accept they have

(occurs) (1) evolved

accept some bacteria

• some bacteria have a mutation/ have a {gene/allele}
(genetic) variation (1) for resistance

• (these) resistant bacteria survive accept the non-

/resistant bacteria reproduce (1) resistant bacteria die
/ the fittest bacteria
survive

ignore immune
bacteria
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Question Indicative content Mark

number

9(c)* Indicative content (6)

AO2 (6 marks) AO2 1

Indicative content

Area 1 - Age of tools

• Younger rock layers towards top / older rock

layers lower down
• C is older than B which is older than A
• Tools can be compared with other fossils
from known time period
• Rocks can be dated, e.g. radiometric dating

Area 2 - Quality of tools

• A is the most sophisticated / most finely

worked / more specialised / more refined /
more symmetrical
• B shows some evidence of being worked / is
rough
• C most basic / most simple / less
sophisticated / unworked

Area 3 – Skills and intelligence

• tools show evidence of greater human

manipulation / greater skill (between C and
A)
• higher intelligence in more recent (species
of) humans

(Total for Question 9 = 13 marks)

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Level Mark Descriptor

0 • No awardable content

Level 1 1-2 • The explanation attempts to link and apply knowledge and
understanding of scientific ideas, flawed or simplistic
connections made between elements in the context of the
question.
• Lines of reasoning are unsupported or unclear. (AO2)
Level 2 3-4 • The explanation is mostly supported through linkage and
application of knowledge and understanding of scientific
ideas, some logical connections made between elements
in the context of the question.
• Lines of reasoning mostly supported through the
application of relevant evidence. (AO2)
Level 3 5-6 • The explanation is supported throughout by linkage and
application of knowledge and understanding of scientific
ideas, logical connections made between elements in the
context of the question.
• Lines of reasoning are supported by sustained application
of relevant evidence. (AO2)
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Level Mark Additional Guidance General additional guidance –

The level is determined by the number of areas covered within the response.

The mark within the band is determined by the presence of linkage between
areas.

0 No rewardable material.

Level 1 1–2 Possible candidate responses

A simple observation with a brief The deeper the rock the older it is.
explanation from one of the three areas of
Tool B is older than tool A. Tool C is just a rock but tool B has been made.
indicative content.
Tool C is older than B/A because it is found in deeper rock.

Level 2 3–4 Possible candidate responses

A simple explanation from at least two Tool B is older than tool A. Tool C is older than tool B. Tool B has been
areas of indicative content. shaped by a more intelligent human.

Tool C is older than tool B and tool A is more sophisticated than tool B
showing that the brain of the human who made tool A is more developed.

Level 3 5–6 Additional guidance Possible candidate responses

Tool C is older than tool B which is older than tool A. Older rocks are found
A detailed explanation linking ideas from all further down. The person who made / used tool A was more intelligent.
three areas of indicative content.

Tool A was found in younger rock because it is higher up in the cliff. Tool A is
more sophisticated which suggests the person who made it is more intelligent
than the person who made tool A or B.
Production of tool A suggests more skilled / intelligent humans when
compared with tools B and C which were found in deeper rocks.
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Question Answer Additional guidance Mark

number

10(a)(i) full marks for correct (3)

answer with no working
(292 + 301 + 297) = 890 (1) AO2

ecf from mp1

(890÷3) 296.7 (1)
allow 296.67 or answers
correct to any number of
decimal places for 2 marks
including the dot to show
recurring numbers

given to 3 s.f. (1)

ecf from mp2

297
accept 296 for 2 marks

award 1 mark for 296.6/

296.66

Question Answer Additional Mark

number guidance

10(a)(ii) Any one from: (1)

• as age increases focusing accept a conclusion AO3 2a

distance increases /ORA (1) that links age group
to a focus distance

ignore cannot see

• as age increases people
objects in the
{become more long-sighted /
distance
cannot see objects close up
clearly} / ORA (1)

• different people of the same

age have different focusing
distances (1)
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Question Answer Additional Mark

number guidance

10(a)(iii) Any two from: (2)

• use more people /repeat the AO3/3b

test (with more people) (1)

• use more ages (1)

• repeat the test for each person

(1)

accept named
• controlling a variable in the
variable e.g. sex
people selected (1)

ignore defects in
• reference to no other eye
distance vision
defect / health issues (1)
accept named
• controlling {external factors e.g. light
environment / test used} (1) levels / same book /
same font

Question Answer Mark

number

10(b) (1)
C cones
AO1 (1)

4b. The only correct answer is C

A is not correct because the iris controls the size of the pupil

B is not correct because the lens focuses the light rays onto
the retina
D is not correct because the cornea refracts light
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Question Answer Additional guidance Mark

number

10(c)(i) An answer including: (2)

AO1

• light rays {refracted / bent} reject for references to

{at the cornea /by the lens} light going
(1) through/refracted by
the iris

accept (refracted) onto

• (light rays) {converge / focus} the retina
on the retina / focal point is
on the retina (1)
accept rods / cones for
retina

ignore back of the

eye/optic nerve

Question Answer Additional guidance Mark

number

10(c)(ii) An explanation linking two from: (2)

AO2
• lens X which is a
accept a {concave
{diverging/concave lens} (1)
/diverging} lens

reject lens Y

• {lens X/a diverging lens/a

concave lens} will
{diverge/spread} out the
light rays (1)

(Total for Question 10 = 11 marks)

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