Cambridge O Level
BIOLOGY
5090/11
Paper 1 Multiple Choice
May/June 2021
1 hour
You must answer on the multiple choice answer sheet.
*8832690463*
You will need: Multiple choice answer sheet
Soft clean eraser
Soft pencil (type B or HB is recommended)
INSTRUCTIONS
 There are forty questions on this paper. Answer all questions.
 For each question there are four possible answers A, B, C and D. Choose the one you consider correct
and record your choice in soft pencil on the multiple choice answer sheet.
 Follow the instructions on the multiple choice answer sheet.
 Write in soft pencil.
 Write your name, centre number and candidate number on the multiple choice answer sheet in the
spaces provided unless this has been done for you.
 Do not use correction fluid.
 Do not write on any bar codes.
 You may use a calculator.
INFORMATION
 The total mark for this paper is 40.
 Each correct answer will score one mark.
 Any rough working should be done on this question paper.
This document has 16 pages.
IB21 06_5090_11/4RP
© UCLES 2021
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2
1
2
Which structures are present in plant cells but not in animal cells?
A
cell membrane, cytoplasm, chloroplasts
B
cell wall, chloroplasts, sap vacuole
C
cell wall, cell membrane, cytoplasm
D
cytoplasm, nucleus, chloroplasts
A piece of plant tissue is transferred from a beaker of water into a concentrated sugar solution.
Which row describes what happens?
3
volume of tissue cells
A
into the cells
decreases
B
into the cells
increases
C
out of the cells
decreases
D
out of the cells
increases
Which statements about active transport are correct?
A
4
movement of water
1
Ions move from a region of high concentration to a region of low concentration.
2
Ions move across the cell membrane.
3
Energy released during respiration is used to move ions into or out of a cell.
1, 2 and 3
B
1 and 2 only
C
1 and 3 only
D
2 and 3 only
What is a correct description of enzymes?
A
biological catalysts made of lipids
B
biological catalysts made of proteins
C
catalysts that slow down chemical reactions and are changed by the reaction
D
catalysts that speed up chemical reactions and are changed by the reaction
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5
An investigation was carried out into the effects of light intensity and carbon dioxide concentration
on the rate of photosynthesis.
Which graph shows the results of this investigation?
A
B
rate of
photosynthesis
rate of
photosynthesis
0
0
0
0
light intensity
light intensity
C
D
light
intensity
rate of
photosynthesis
0
0
0
0
light intensity
rate of photosynthesis
key
high carbon dioxide concentration
intermediate carbon dioxide concentration
low carbon dioxide concentration
6
What describes the upper cuticle of a leaf?
A
a permeable layer allowing water to enter the leaf
B
a single layer of cells containing many chloroplasts
C
a single layer of transparent cells allowing light to enter the leaf
D
a thin non-cellular layer preventing water loss from the leaf
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5090/11/M/J/21
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4
7
Plants growing in soil lacking magnesium ions have poor growth.
What causes their poor growth?
8
9
A
They cannot form cellulose for new cell walls.
B
They cannot form chlorophyll for photosynthesis.
C
They cannot produce amino acids to form proteins.
D
They cannot take in mineral ions from the soil.
Which statement about diets is correct?
A
A diet providing all the needs of an average man aged 70 can lead to malnutrition in an
active boy aged 14.
B
Malnutrition can only occur if the body receives less of a nutrient than it requires.
C
Protein requirements in the diet increase throughout a person’s life.
D
Very young children require a greater total energy intake than active adults.
The diagram shows part of the human alimentary canal and associated organs.
5
1
4
2
3
Which row describes the functions of parts shown in the diagram?
structure
function
structure
function
A
1
digestion of protein
3
absorption of the products
of digestion
B
2
emulsifying fats
3
absorption of amino
acids and glucose
C
4
production of bile
5
making digestive enzymes
D
4
storing digestive enzymes
2
making digestive enzymes
© UCLES 2021
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5
10 What is not an example of assimilation?
A
synthesis of glycogen from glucose
B
synthesis of fats from fatty acids and glycerol
C
synthesis of glucose from starch
D
synthesis of proteins from amino acids
11 Which feature of a root hair cell helps it take up ions from water in the soil?
A
The cell has a partially permeable cell wall.
B
The cell is able to provide a source of energy.
C
The cell vacuole has a high ion concentration.
D
The cell vacuole has a low water potential.
12 The diagram shows the pathway of water molecules through part of a leaf, seen under a
microscope, in transverse section.
Where does water evaporate?
A
B
C
D
13 Which row describes the functions of the blood components?
plasma
platelets
white blood cells
A
antibody formation
clotting
transport of nutrients
B
clotting
transport of nutrients
antibody formation
C
clotting
antibody formation
transport of nutrients
D
transport of nutrients
clotting
antibody formation
© UCLES 2021
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14 The diagram shows a section through the human heart.
valve 3
valve 2
valve 1
valve 4
chamber X
chamber Y
What will be the state of the valves when the walls of chambers X and Y are contracting?
valves
1
2
3
4
A
closed
open
open
closed
B
closed
open
closed
open
C
open
closed
open
closed
D
open
closed
closed
open
© UCLES 2021
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7
15 The diagram represents the blood supply to the liver and to the kidneys.
1
2
liver
from
ileum
4
kidneys
3
Which vessels contain blood with the highest and lowest concentrations of urea?
highest
lowest
A
1
2
B
1
4
C
3
2
D
3
4
16 What is not a feature of aerobic respiration?
A
It occurs in both plants and animals.
B
It releases a smaller amount of energy than anaerobic respiration.
C
It requires the presence of oxygen.
D
The end products are carbon dioxide and water.
17 In an investigation, scientists treated plant roots with a chemical that stops aerobic respiration.
They observed that after the treatment the plant roots absorbed nitrate ions more slowly.
Which statement explains this observation?
A
Anaerobic respiration does not release energy.
B
The plant cells cannot respire.
C
There is less energy for active transport of nitrate ions.
D
There is less energy for diffusion of nitrate ions.
© UCLES 2021
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18 Why does oxygen enter the blood in the lungs?
A
Aerobic respiration takes place in the lungs.
B
Carbon dioxide diffuses out of the blood into the alveoli.
C
The air in alveoli contains a higher concentration of oxygen than the blood in the lung
capillaries.
D
The air in alveoli contains a lower concentration of oxygen than the blood in the lung
capillaries.
19 The diagram shows structures in a human which form and store urine. Liquids pass through
tubes X, Y and Z in the directions shown by the arrows.
X
kidney
Y
Z
bladder
Which statement about the volume of liquid passing through Y in one day is correct?
A
It is greater than that passing through X.
B
It is less than that passing through Z.
C
It is much less than that passing through X but slightly greater than that passing through Z.
D
It is slightly less than that passing through X but much greater than that passing through Z.
© UCLES 2021
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9
20 The diagram shows the homeostatic control of body temperature.
above normal
temperature
corrective
mechanisms P and Q
body temperature
increases
negative
feedback
normal body
temperature
coordinator
R
normal body
temperature
body temperature
decreases
negative
feedback
below normal
temperature
corrective
mechanisms
What are corrective mechanisms P and Q and coordinator R?
corrective mechanisms
coordinator R
P
Q
A
sweating
more blood flows close
to the skin surface
brain
B
sweating
more blood flows close
to the skin surface
skin
C
shivering
less blood flows close
to the skin surface
brain
D
shivering
less blood flows close
to the skin surface
skin
21 The diagram shows a section through the brain.
Which part of the brain secretes hormones?
D
C
© UCLES 2021
A
B
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22 Which changes occur in the eye when viewing a distant object?
A
1
The ciliary muscles contract.
2
The ciliary muscles relax.
3
The suspensory ligaments are pulled tight.
4
The suspensory ligaments are slackened.
1 and 3
B
1 and 4
C
2 and 3
D
2 and 4
23 The diagram shows three positions, X, Y and Z, where nerve impulses are blocked by a drug.
brain
spinal cord
sensory neurone
Z
X
Y
motor neurone
Which person listed below moves their leg in response to a pinprick, but does not feel it?
A
a person with a block at X
B
a person with a block at Y
C
a person with a block at Z
D
a person with no block
24 Which pair of bones form a hinge joint in the forelimb?
A
humerus and scapula
B
radius and ulna
C
scapula and radius
D
ulna and humerus
© UCLES 2021
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25 What are the effects of drinking a large quantity of alcohol on the human body?
effects on the body
acts as a
reaction time
damages the
A
depressant
decreases
kidney
B
depressant
increases
liver
C
stimulant
increases
kidney
D
stimulant
decreases
liver
26 The diagram shows the structure of a bacterium.
In what way does this differ from a cell of a fungus?
A
The bacterium has a cell membrane.
B
The bacterium has a cell wall.
C
The bacterium has cytoplasm.
D
The bacterium has no true nucleus.
27 Bacteria are involved in the manufacture of which product?
A
alcohol
B
bread
C
yoghurt
D
penicillin
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12
28 These processes occur in living organisms in a food chain.
1
excretion
2
photosynthesis
3
respiration
Which processes would result in a loss of energy from a food chain?
A
1 and 2
B
1 and 3
C
2 only
D
3 only
29 Which statements are correct?
A
1
Energy cannot be recycled in food webs.
2
Producers make their own organic nutrients.
3
The Sun is the principal source of energy input to biological systems.
1, 2 and 3
B
1 and 2 only
C
1 and 3 only
D
2 and 3 only
30 The diagram shows the movement of carbon in the carbon cycle, in gigatonnes per year.
atmosphere
40
20
animals
10
125
plants
60
decomposers
0.1
fossil fuels
How many gigatonnes of carbon are moved by respiration each year?
A
120
B
125
C
130
D
255
31 What are the roles of the female mosquito and the malarial pathogen in the spread of malaria?
female mosquito
malarial pathogen
A
parasite
vector
B
parasite
parasite
C
vector
parasite
D
vector
vector
© UCLES 2021
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32 Which human activity will make the greatest contribution to global warming?
A
cutting down established trees and replanting with young trees
B
cutting down established trees and using the cleared land to raise cattle
C
reducing the use of diesel fuel in public transport vehicles
D
using fewer insecticides and herbicides on farms
33 The diagram shows two onion plants.
flower
small
bulb
stalk
daughter plant
Using the information in the diagram, which statement about these onion plants is correct?
A
Daughter plants are produced from the small bulb by meiosis.
B
Daughter plants produced from the flower are genetically identical to the parent plant.
C
The plants can reproduce sexually and asexually.
D
Two parent plants are required for reproduction.
© UCLES 2021
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34 Six bean seeds were soaked in cold water. Three of them were boiled and cooled. The boiled
and the non-boiled seeds were chopped up and then placed on the surface of agar jelly
containing starch.
After two days, all the seeds were removed and the jelly was tested with iodine solution.
The diagram shows the result of the experiment.
boiled seeds
non-boiled
seeds
key
yellow / brown
colour
blue / black
colour
position of chopped
seeds at start of
experiment
What is the explanation for the results with the non-boiled bean seeds?
A
They absorb iodine.
B
They absorb starch.
C
They contain acid.
D
They contain amylase.
© UCLES 2021
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35 The diagram shows how the blood of a human fetus flows close to the mother’s blood in the
placenta.
mother’s
blood
blood of
fetus
X
Y
Which substances are present at X in higher concentrations than at Y?
A
carbon dioxide and glucose
B
carbon dioxide and urea
C
glucose and oxygen
D
glucose and urea
36 Why will antibiotics not cure a person with HIV infection?
A
Viruses are much smaller than bacteria.
B
Viruses are not affected by antibiotics.
C
Viruses are made from protein and DNA.
D
Viruses are not pathogens.
37 Chromosomes, DNA molecules and genes are pieces of inherited material with different sizes.
Which statement describes the relationship between these pieces of inherited material?
A
A chromosome is larger than a gene.
B
A gene is larger than a chromosome.
C
Multiple chromosomes make up a DNA molecule.
D
Multiple DNA molecules make up a gene.
© UCLES 2021
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38 Earlobes can either be attached to the cheek or be ‘free’ (unattached). This characteristic is
controlled by a single gene.
The allele for attached earlobes is recessive.
The diagram shows the inheritance of attached earlobes in one family.
1
2
3
4
key
male with free earlobes
5
6
7
8
female with free earlobes
male with attached earlobes
female with attached earlobes
9
Which two individuals must be heterozygous for earlobe attachment?
A
1 and 7
B
3 and 4
C
5 and 8
D
6 and 9
39 Which statements about natural selection are correct?
natural selection can
lead to better adapted
species surviving
natural selection can
lead to extinction
of a species
natural selection can
lead to gene
mutations occurring
A
true
true
true
B
true
true
false
C
true
false
true
D
false
true
true
40 Which feature of a cereal crop cannot be improved by selective breeding alone?
A
ability to fix nitrogen
B
resistance to drought
C
tolerance to low temperatures
D
number of seeds produced
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the
publisher will be pleased to make amends at the earliest possible opportunity.
To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge
Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download
at www.cambridgeinternational.org after the live examination series.
Cambridge Assessment International Education is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of the University of
Cambridge Local Examinations Syndicate (UCLES), which itself is a department of the University of Cambridge.
© UCLES 2021
5090/11/M/J/21
Cambridge O Level
BIOLOGY
5090/11
Paper 1 Multiple Choice
May/June 2021
MARK SCHEME
Maximum Mark: 40
Published
This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination.
Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.
Cambridge International will not enter into discussions about these mark schemes.
Cambridge International is publishing the mark schemes for the May/June 2021 series for most Cambridge
IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.
This document consists of 3 printed pages.
© UCLES 2021
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5090/11
Cambridge O Level – Mark Scheme
PUBLISHED
Question
Answer
May/June 2021
Marks
1
B
1
2
C
1
3
D
1
4
B
1
5
A
1
6
D
1
7
B
1
8
A
1
9
A
1
10
C
1
11
B
1
12
C
1
13
D
1
14
A
1
15
B
1
16
B
1
17
C
1
18
C
1
19
D
1
20
A
1
21
C
1
22
C
1
23
C
1
24
D
1
25
B
1
26
D
1
27
C
1
28
B
1
© UCLES 2021
Page 2 of 3
5090/11
Cambridge O Level – Mark Scheme
PUBLISHED
Question
Answer
May/June 2021
Marks
29
A
1
30
A
1
31
C
1
32
B
1
33
C
1
34
D
1
35
B
1
36
B
1
37
A
1
38
A
1
39
B
1
40
A
1
© UCLES 2021
Page 3 of 3
Cambridge O Level
BIOLOGY
5090/12
Paper 1 Multiple Choice
May/June 2021
1 hour
You must answer on the multiple choice answer sheet.
*8469910641*
You will need: Multiple choice answer sheet
Soft clean eraser
Soft pencil (type B or HB is recommended)
INSTRUCTIONS
 There are forty questions on this paper. Answer all questions.
 For each question there are four possible answers A, B, C and D. Choose the one you consider correct
and record your choice in soft pencil on the multiple choice answer sheet.
 Follow the instructions on the multiple choice answer sheet.
 Write in soft pencil.
 Write your name, centre number and candidate number on the multiple choice answer sheet in the
spaces provided unless this has been done for you.
 Do not use correction fluid.
 Do not write on any bar codes.
 You may use a calculator.
INFORMATION
 The total mark for this paper is 40.
 Each correct answer will score one mark.
 Any rough working should be done on this question paper.
This document has 20 pages. Any blank pages are indicated.
IB21 06_5090_12/4RP
© UCLES 2021
[Turn over
2
1
2
Which row is correct?
cell
tissue
organ
organ system
A
chloroplast
mesophyll
liver
digestive
B
sap vacuole
red blood cell
blood
nervous
C
red blood cell
sap vacuole
stomach
liver
D
neurone
vascular bundle
leaf
excretory
A piece of plant tissue is transferred from a beaker of water into a concentrated sugar solution.
Which row describes what happens?
3
movement of water
volume of tissue cells
A
into the cells
decreases
B
into the cells
increases
C
out of the cells
decreases
D
out of the cells
increases
The following statements refer to the movement of substances into and out of cells.
1
Energy from respiration is required.
2
Energy from respiration is not required.
3
Movement occurs down a concentration gradient.
4
Net movement is from a region of higher concentration to a region of lower
concentration.
5
Net movement is from a region of lower concentration to a region of higher
concentration.
Which statements apply to active transport?
A
4
1 and 3
B
1 and 5
C
2 and 4 only
D
2, 4 and 5
Which word describes an enzyme that has its active site changed by high temperature?
A
denatured
B
destroyed
C
deleted
D
distorted
© UCLES 2021
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3
5
Hydrogencarbonate indicator changes colour according to the concentration of carbon dioxide
present.
The table shows how hydrogencarbonate indicator changes colour.
colour of
hydrogencarbonate
indicator
concentration of carbon
dioxide
orange
atmospheric carbon dioxide
concentration
yellow
higher than atmospheric
carbon dioxide concentration
purple
lower than atmospheric carbon
dioxide concentration
Four test-tubes were set up under different conditions. The colour of hydrogencarbonate indicator
in each test-tube at the start of the experiment and after 1 hour is also shown.
Which test-tube shows that the rates of photosynthesis and respiration are the same?
A
B
C
stopper
stopper
hydrogencarbonate
indicator
hydrogencarbonate
indicator
aquatic
snail
aquatic
plant
aquatic
plant
foil
6
D
in darkness
in dim light
in light
in light
orange to yellow
stays orange
orange to purple
orange to yellow
What describes the upper cuticle of a leaf?
A
a permeable layer allowing water to enter the leaf
B
a single layer of cells containing many chloroplasts
C
a single layer of transparent cells allowing light to enter the leaf
D
a thin non-cellular layer preventing water loss from the leaf
© UCLES 2021
5090/12/M/J/21
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7
A lack of certain mineral ions affects the growth of young plants.
Which effects are caused by a lack of magnesium ions and a lack of nitrate ions?
8
lack of magnesium ions
lack of nitrate ions
A
the leaves become dark green
overall growth is stunted
B
the leaves go yellow in patches
the plant is unable to form proteins
C
the plant is unable to form enzymes
the plant is unable to form starch
D
the plant is unable to form root hairs
the leaves become bright green
The graph shows some of the nutrients found in peanuts.
100
75
percentage
nutrient
content
50
25
0
sugars
fats
proteins
nutrients
A student tested peanuts with four food tests.
Which row shows the results?
Benedict’s
test
biuret test
ethanol
emulsion test
iodine test
A
yellow
purple
white
brown
B
black
blue
white
black
C
red
purple
clear
blue
D
blue
blue
clear
brown
© UCLES 2021
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5
9
Which row shows factors that may contribute to famine?
climate change
causing
drought
destruction of
tropical forest
flooding
increased
human
population
increased use
of fertilisers
A
yes
yes
yes
no
no
B
yes
no
yes
yes
no
C
no
yes
no
yes
yes
D
yes
no
no
yes
yes
10 The diagram shows part of the human alimentary canal and associated organs.
5
1
4
2
3
Which row describes the functions of parts shown in the diagram?
structure
function
structure
function
A
1
digestion of protein
3
absorption of the products
of digestion
B
2
emulsifying fats
3
absorption of amino
acids and glucose
C
4
production of bile
5
making digestive enzymes
D
4
storing digestive enzymes
2
making digestive enzymes
© UCLES 2021
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6
11 How does water enter root hair cells?
A
from high to low water potential by active transport
B
from high to low water potential by osmosis
C
from low to high water potential by active transport
D
from low to high water potential by osmosis
12 The diagram shows the pathway of water molecules through part of a leaf, seen under a
microscope, in transverse section.
Where does water evaporate?
A
B
C
D
13 Which row describes the functions of the blood components?
plasma
platelets
white blood cells
A
antibody formation
clotting
transport of nutrients
B
clotting
transport of nutrients
antibody formation
C
clotting
antibody formation
transport of nutrients
D
transport of nutrients
clotting
antibody formation
© UCLES 2021
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7
14 The diagram shows how the volume of blood in the left ventricle of a human heart changes during
one heart beat.
When is the left ventricle contracting?
A
volume of
blood / ml
B
C
D
70
60
50
40
30
20
10
0
0
0.8
0.4
time / seconds
15 The diagram represents the blood supply to the liver and to the kidneys.
1
liver
2
from
ileum
4
kidneys
3
Which vessels contain blood with the highest and lowest concentrations of urea?
highest
lowest
A
1
2
B
1
4
C
3
2
D
3
4
© UCLES 2021
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8
16 Which statement is true for aerobic respiration?
A
Aerobic respiration in humans occurs mainly in the alveoli.
B
Aerobic respiration releases less energy than anaerobic respiration.
C
Glucose is broken down to smaller molecules in aerobic respiration.
D
Oxygen is broken down to release energy in aerobic respiration.
17 The graph shows the concentration of substance X in a person’s blood, before, during and after
exercise.
concentration
of substance
X in the blood
time
at
rest
exercise stops
exercise starts
What is substance X?
A
alcohol
B
glycogen
C
lactic acid
D
urea
18 During exercise, a person breathes more deeply and more frequently.
Which is a result of this?
A
Carbon dioxide is removed more rapidly.
B
Heat loss is decreased.
C
Less glucose is delivered to the working muscles.
D
Less oxygen diffuses into the blood.
© UCLES 2021
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9
19 The diagram shows structures in a human which form and store urine. Liquids pass through
tubes X, Y and Z in the directions shown by the arrows.
X
kidney
Y
Z
bladder
Which statement about the volume of liquid passing through Y in one day is correct?
A
It is greater than that passing through X.
B
It is less than that passing through Z.
C
It is much less than that passing through X but slightly greater than that passing through Z.
D
It is slightly less than that passing through X but much greater than that passing through Z.
20 Which response will happen if a person walks into a cold environment?
A
Hair erector muscles cause the body hairs to lay flat on the skin.
B
More blood flows in the capillaries near the surface of the skin.
C
Large body muscles contract and relax rapidly.
D
The sweat glands produce a larger amount of sweat.
© UCLES 2021
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10
21 The diagram shows the human brain.
What is the name of the shaded part of the brain?
A
cerebellum
B
cerebrum
C
hypothalamus
D
medulla
22 What happens in the eye to produce the pupil reflex to bright light?
A
1
ciliary muscle contraction
2
circular muscle contraction
3
radial muscle relaxation
4
suspensory ligaments pulled tight
1 and 3
B
1 and 4
C
2 and 3
D
2 and 4
23 The diagram shows three positions, X, Y and Z, where nerve impulses are blocked by a drug.
brain
spinal cord
sensory neurone
Z
X
Y
motor neurone
Which person listed below moves their leg in response to a pinprick, but does not feel it?
A
a person with a block at X
B
a person with a block at Y
C
a person with a block at Z
D
a person with no block
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24 The diagram shows how antagonistic muscles are arranged in the arm.
1
2
Which row describes the muscle action when the arm is straightened?
muscle 1
muscle 2
A
contracts
expands
B
contracts
relaxes
C
expands
contracts
D
relaxes
contracts
25 Electronic cigarettes are a cigarette substitute allowing nicotine to be inhaled without the other
components found in cigarette smoke.
Which effects of cigarette smoking will also be effects of using electronic cigarettes?
A
Smoking increases heart rate, narrows the arterioles and increases blood pressure.
B
Smoking irritates the airways and increases mucus production.
C
Smoking reduces oxygen carried by red blood cells and reduces oxygen delivered to the
tissues.
D
Smoking narrows the airways and increases coughing.
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26 The diagram shows the structure of a bacterium.
In what way does this differ from a cell of a fungus?
A
The bacterium has a cell membrane.
B
The bacterium has a cell wall.
C
The bacterium has cytoplasm.
D
The bacterium has no true nucleus.
27 Which microorganisms are involved in the decomposition of dead plant material?
bacteria
fungi
viruses
A
yes
no
yes
B
yes
yes
no
C
no
yes
yes
D
yes
no
no
28 What is the reason for describing the flow of energy through an ecosystem as non-cyclic?
A
The energy cannot be returned to its original source.
B
The energy cannot have its form changed within an organism.
C
The energy can only be passed on in its original form.
D
The energy can only be transferred to a larger organism.
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29 The diagram shows a complete food web.
organism 1
organism 2
organism 5
organism 7
organism 3
organism 6
organism 8
organism 4
Which row identifies examples of the types of organisms in this food web?
carnivore
consumer
herbivore
producer
A
2
7
8
4
B
4
2
3
1
C
6
4
8
1
D
7
3
2
4
30 The diagram shows part of the carbon cycle.
carbon dioxide
in air and water
X
Y
decay
animals
green
plants
Z
death
fossilisation
What do X, Y and Z represent?
X
Y
Z
A
combustion
respiration
ingestion
B
combustion
ingestion
respiration
C
photosynthesis
respiration
combustion
D
photosynthesis
combustion
respiration
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31 Coastal marine regions are environments with a rich plant and animal diversity.
Which process would reduce the biodiversity of these environments?
A
banning fishing during the fish breeding season
B
increasing the mesh size for any fishing nets used
C
stopping the release of raw sewage into the sea
D
allowing fishing methods that disturb the seabed
32 Hardwood trees in tropical rainforests are often harvested for timber. A single quick-growing crop,
such as palm oil, is then grown on the same land.
What effect will removing the rainforest have on the environment?
A
decreased run off into rivers and flooding
B
improved soil structure and soil nutrients
C
reduced soil erosion by wind and rain
D
reduced biodiversity of the area
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33 The diagram shows part of a Bryophyllum plant.
small plants
leaf
small plant falls to the ground
and grows into a new plant
Which best describes how the new plants are produced?
type of reproduction
type of cell division
asexual
reproduction
sexual
reproduction
meiosis
mitosis
A
key
B
= yes
C
= no
D
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34 Six bean seeds were soaked in cold water. Three of them were boiled and cooled. The boiled
and the non-boiled seeds were chopped up and then placed on the surface of agar jelly
containing starch.
After two days, all the seeds were removed and the jelly was tested with iodine solution.
The diagram shows the result of the experiment.
boiled seeds
non-boiled
seeds
key
yellow / brown
colour
blue / black
colour
position of chopped
seeds at start of
experiment
What is the explanation for the results with the non-boiled bean seeds?
A
They absorb iodine.
B
They absorb starch.
C
They contain acid.
D
They contain amylase.
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35 The diagram shows how the blood of a human fetus flows close to the mother’s blood in the
placenta.
mother’s
blood
blood of
fetus
X
Y
Which substances are present at X in higher concentrations than at Y?
A
carbon dioxide and glucose
B
carbon dioxide and urea
C
glucose and oxygen
D
glucose and urea
36 The table shows four ways in which diseases may be passed from one human to another.
Which row shows the ways in which HIV may be transferred?
transferred from person to person through
air
blood
saliva
semen
A
yes
no
yes
no
B
yes
no
no
yes
C
no
yes
yes
no
D
no
yes
no
yes
37 Which sex chromosomes are present in every sperm cell?
A
X chromosome only
B
Y chromosome only
C
X or Y chromosome only
D
X and Y chromosomes
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38 Earlobes can either be attached to the cheek or be ‘free’ (unattached). This characteristic is
controlled by a single gene.
The allele for attached earlobes is recessive.
The diagram shows the inheritance of attached earlobes in one family.
1
2
3
4
key
male with free earlobes
5
6
7
8
female with free earlobes
male with attached earlobes
female with attached earlobes
9
Which two individuals must be heterozygous for earlobe attachment?
A
1 and 7
B
3 and 4
C
5 and 8
D
6 and 9
39 Which statements about natural selection are correct?
natural selection can
lead to better adapted
species surviving
natural selection can
lead to extinction
of a species
natural selection can
lead to gene
mutations occurring
A
true
true
true
B
true
true
false
C
true
false
true
D
false
true
true
40 Some stages in the production of human insulin are listed.
1
Genetically modified E. coli bacteria are grown in large fermenters.
2
The gene for human insulin is inserted into the DNA of a bacterium called E. coli.
3
The gene for human insulin is obtained from human pancreas cells.
4
Human insulin is extracted and purified.
What is the correct sequence of these stages?
A
3124
B
4321
C
3241
D
3214
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reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the
publisher will be pleased to make amends at the earliest possible opportunity.
To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge
Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download
at www.cambridgeinternational.org after the live examination series.
Cambridge Assessment International Education is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of the University of
Cambridge Local Examinations Syndicate (UCLES), which itself is a department of the University of Cambridge.
© UCLES 2021
5090/12/M/J/21
Cambridge O Level
BIOLOGY
5090/12
Paper 1 Multiple Choice
May/June 2021
MARK SCHEME
Maximum Mark: 40
Published
This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination.
Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.
Cambridge International will not enter into discussions about these mark schemes.
Cambridge International is publishing the mark schemes for the May/June 2021 series for most Cambridge
IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.
This document consists of 3 printed pages.
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5090/12
Cambridge O Level – Mark Scheme
PUBLISHED
Question
Answer
May/June 2021
Marks
1
D
1
2
C
1
3
B
1
4
A
1
5
B
1
6
D
1
7
B
1
8
A
1
9
B
1
10
A
1
11
B
1
12
C
1
13
D
1
14
B
1
15
B
1
16
C
1
17
C
1
18
A
1
19
D
1
20
C
1
21
A
1
22
C
1
23
C
1
24
D
1
25
A
1
26
D
1
27
B
1
28
A
1
© UCLES 2021
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5090/12
Cambridge O Level – Mark Scheme
PUBLISHED
Question
Answer
May/June 2021
Marks
29
A
1
30
C
1
31
D
1
32
D
1
33
B
1
34
D
1
35
B
1
36
D
1
37
C
1
38
A
1
39
B
1
40
D
1
© UCLES 2021
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