2020_Combined science_olevel_nov_paper1

Extracted Content: 2020_Combined science_olevel_nov_paper1

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ZIMBABWE SCHOOL EXAMINATIONS COUNCIL

General Certificate of Education Ordinary Level

COMBINED SCIENCE 4003/1
PAPER | Multiple Choice
NOVEMBER 2020 SESSION 1 hour

Additional materials:
Multiple Choice answer sheet
Soft clean eraser
Soft pencil (type B or HB is recommended)
Calculator (optional)

INSTRUCTIONS TO CANDIDATES

Do not open this booklet until you are told to do so.
Write your name, Centre number and candidate number on the answer sheet in the spaces
provided unless this has already been done for you.

There are forty questions in 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 separate
answer sheet.

Read very carefully the instructions on the answer sheet.
INFORMATION FOR CANDIDATES
Each correct answer will score one mark.

A mark will not be deducted for a wrong answer. Any rough working should be done in this
booklet.

This question paper consists of 16 printed pages.

Copyright: Zimbabwe School Examinations Council, N2020.

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1. Which one is a biological component of an ecosystem? A air B soil C_ water

D humus

2. The diagram shows some stages in the nitrogen cycle.

Which arrow, A, B, C or D, represents the action of decomposers?

plant
protein

nitrates

atmospheric
nitrogen

3. Which equation shows the process of anaerobic respiration in humans?
A glucose —-+ lactic acid + energy
B_ glucose + —> ethanol + energy
C_ glucose —+ lactic acid + carbon dioxide + energy

D glucose + oxygen ——> ethanol + carbon dioxide + energy

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During germination, the sced coat breaks due to the uptake of

carbon dioxide.

1~

mineral salts.
C_ oxygen.

D_ water.

Which organ produces bile?
A. liver

B_ stomach

C_ pancreas

D_ gall bladder

Plasmolysis causes the

A cell membrane to move away from the cell wall.
B_ cell membrane to move towards the cell wall.

C_ turgor pressure inside the cell to increase.
D

water molecules to move into the cell.

Which factor decreases the rate of transpiration in a plant?
A large leaf surface area

B high light intensity

C_ high temperature

D_ high humidity

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8.

10.

The diagram shows a model of the human alimentary canal.

Which part, A, B, C ar D, represents where ingestion takes place?

alimentary
canal

semi-permeable
tube

stand

Which type(s) of blood vessels contain(s) valves?

A
B
c

D

veins and capillaries
capillaries
arteries

veins

Which statement about asexual reproduction is true?

A

B
Cc
D

Offspring are resistant to diseases that affect parents.
Offspring grow far away from parents.
Many new plants are obtained from sceds.

Offspring are genetically identical to their parents.

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L, The diagram shows the female reproductive system.

Where does fertilisation take place?

A
\
|

12. The diagram shows an embryo attached to the placenta.

4

Which arrow, A, B, C or D, shows the movement of nutrients?

placenia

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13.

14,

15.

16.

Hormones that are found in the contraceptive pill work by
A preventing maturing of the egg.

B_ killing sperm cells in the oviduct.

C preventing fertilisation of the egg.
D

preventing implantation of the embryo.

What is the effect of HIV on the human body?

A HIV makes it easier for pathogens to invade cells.
B_ HIV reduces the body’s resistance to infection.

C_ HIV reduces the number of red blood cells.

D_ HIV destroys all body tissues.

Which method is used to produce concentrated ethanol from a dilute
ethanol solution?

filtration
decanting

simple distillation

5 AO Be PY}

fractional distillation

What is the electronic configuration of nitrogen, e N?

2,5
2, 2,3

2, 8,4

5 A & p>

2, 2, 8 2

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17.

18.

19.

Which one is an Isotope of #0 ?

m6)
8.0
ne
16 O

57 Ow OF

Element X has the electronic structure 2, 8, 2.

What is the formula of its chloride?

A XCl
B XCl,
c X,cl
D

XC,

What is the concentration of sodium hydroxide solution which is prepared

by dissolving 40 g of sodium hydroxide pellets in 50 dm’ of distilled water?
[Molecular mass of NaOH is 40 g]

A 0.02 mol/dm
B 08mol/dm
C 1.0 mol/dm’

D 2000.0 mol/dm’

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20. The diagram shows a blast furnace.

What is the function of the opening labelled X?
A toremove slag
Bt remove iron
C_ to allow hot air in
D

to allow raw materials in

21. Which industrial gas, produced from the electrolysis of water, is used in
hospitals?

ammonia

~-]

hydrogen

a

nitrogen

i]

oxygen

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22.

Which one is not a use of chlorine?
A sterilising water

B as anelectrolyte

C making domestic bleaches

D_ manufacture of plastics

The diagram shows incomplete apparatus needed for the electrolysis of
water.

What is gas X?
A chlorine
B hydrogen
C_ nitrogen

D oxygen
During the electroplating of an iron nail with copper,

hydrogen gas is produced at the cathode.

A
B the copper sulphate solution tums green.
C_ the cathode increases in mass.

D

the anode increases in mass.

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25.

26.

27,

28.

10

Which catalyst is used in the production of ammonia?
A iron

B rhodium

C platinum

D_ vanadium (V) oxide

Global warming is caused by
A combustion of fuels.

B_ formation of ice.

C rise in sea level.
D

reforestation.

To which homologous series does ethanol belong?
A alkanes

B alkenes

C_ alkynes

D alcohols

What is the S.1 unit of volume?
A cm

B cm

Cm

D m'

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29.

30.

11

The sketch graph shows temperature changes during a day.

4am 8am 12 noon 4pm 8 pm

What is the approximate temperature difference between the hottest and
coldest time of the day?

A 5%

B 26°C
Cc 30°C
D 35°C

A beaker of water is heated at the base.
Why does the water at the base rise?

It contracts and becomes less dense,

&

It contracts and becomes more dense.

a

It expands and becomes less dense.

S

It expands and becomes more dense.

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3.

32.

33.

12

A hot iron bar and a cold iron bar are placed next to each other as shown by
the diagram.

Rap

hot cold
iron bar iron bar

Which material can be used to fill up the gap so that heat can be transmitted
the fastest?

A metal

B wood

C water

D air

A negatively charged sphere is suspended by a thread.

What happens to the sphere when a negatively charged rod is brought near
it?

the sphere is attracted to the rod

the sphere is repelled by the rod

the sphere reduces in size

ee A BB Pp

the sphere increases in size

What is the function of a petrol filter in a carburetor?
A to compress the fuel-air mixture
to mix the fuel and air

to clean the fuel

2 A 8

to clean the air

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13

34. The diagram below shows the magnetic field pattern in a solenoid.

solenoid

The magnetic field strength is increased by

A reducing the current in the solenoid.

1-]

increasing the current in the solenoid.

‘P)

increasing the diameter of the solenoid.

J

reducing the number of turns in the solenoid.

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14

35. The diagram shows a battery connected to two 6 Q resistors.

6.0 Q 6.0 2

What is the total resistance of the circuit?

A 0.33Q

B 3.00

C 6.002

D 12.002
36. What is pressure exerted on a 2 m_ surface when a force of 20 N is applied

on it?

A 0.1 Pa
B 10.0 Pa
C 38.0 Pa
D 40.0 Pa

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37.

38.

39.

15

The diagram shows a machine lifting a load.

How is the mechanical advantage, MA, calculated?
A 300N x 1200N
B 300N+1200N
C 1200N—300N
D

1200 N+ 300N

A cellphone is described as
A ademodulator.

Ba modulator.

Can amplifier.
D

a transceiver.

The flow chart shows part of the processing of a signal.

[receiver] ~~? [decoder] ~~” [human ]

What is the function of the decoder?

to amplify the signal

ie}

to shorten the wave

io}

to mix the sound wave with the carrier wave

~]

to separate the sound wave from the carrier wave

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40. The diagram shows a 3-pin plug.

At which position, A, B, C or D, is the live wire connected?

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