CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 1
Answers
1
a
Nucleus, mitochondria
[2]
b Put the model into a box to represent a cell wall.
2
a
Add some green peas to represent chloroplasts.
[2]
Tissue
[1]
b Controls the activities of the cell.
3
a
[1]
They contain haemoglobin, which carries oxygen.
They have no nucleus, to make more space for carrying oxygen.
[2]
b The function of root hair cells is to absorb water and mineral ions (from the soil).
[1]
They have a long extension/a large surface area to help them to do this.
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
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CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 2
Answers
1
Liquid
[1]
2
a
K
[1]
b Ar
[1]
3
a
Liquid
[1]
b The diagram should show circles of the same size arranged in regular rows with
all particles touching.
[1]
In a mixture, the substances are not joined together to make a new substance, but are
still able to be separated. In a compound, the substances are joined together to make
a new substance.
[1]
5
You need to place your eye in line with the meniscus so that you read the scale accurately.
[1]
6
If you leave ice in a warm place it melts and becomes liquid water. The temperature at
which a solid melts is called the melting point.
4
If you heat water until its temperature reaches 100°C, it will boil. Now, all of the water
rapidly changes to water vapour. 100°C is the boiling point of water.
7
The temperatures at which a substance melts and boils are two of its properties.
[2]
The columns are called groups.
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
2
CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 3
Answers
1
As the mass of a planet increases the strength of gravity on the planet increases.
OR As the mass of a planet decreases the strength of gravity on the planet decreases.
[1]
800 × 5 = 4000
[1]
N or newtons
[1]
Gravity (from the Moon)
[1]
Pulls on the water
[1]
4
Any two from: gravitational potential, chemical, thermal.
[2]
5
Any three from:
• use a thermometer
• measure the temperature of the tea
• at regular intervals/after a stated time
• temperature of the tea will decrease
• temperature of a named object in the surroundings (e.g. table under the cup/air
above the cup) will increase.
[3]
2
3
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
3
CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 4
Answers
1
a
A group of organisms that can reproduce to produce fertile offspring.
[2]
b Accept any question that distinguishes between the two snakes, such as:
• Does it have stripes?
• Does it have a diamond pattern?
[1]
Note that the question must not be comparative
2
a
Any two from sensitivity, nutrition and movement.
[2]
b Respiration - releasing energy from food inside cells
Growth – a permanent increase in size
3
a
Excretion - removing unwanted substances from the body
[3]
They cannot carry out the seven characteristics of living things.
[1]
Accept any named characteristic except reproduction; if reproduction is given, the answer must
also say that they cannot do this on their own
b They can reproduce.
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
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CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 5
Answers
1
Ductile – can be drawn out into strands or wires
Malleable – can easily be hammered into shape
Brittle – breaks with a snap
[2]
2
Do not conduct heat
[1]
3
a
An alloy of aluminium is used for building aeroplanes because it is light and stronger than
pure aluminium.
[1]
b Silver is too expensive to use for coins and it is not hard enough to withstand
the use coins get.
4
Any one from: wear safety glasses (because the solution may spit);
use tongs to handle the hot evaporating basin.
5
a
[1]
[1]
Acid or acidic
[1]
b Green
c
[1]
Universal indicator
[1]
d 7 or pH 7
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
5
CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 6
Answers
A sound wave
[1]
Reflects off the wall.
[1]
2
Tectonic plates
[1]
3
a
False
[1]
b True
[1]
a The Moon comes between the Sun and Earth: the Moon passes in front of the Sun.
[1]
1
4
The Sun can only be seen in the day.
[1]
b Do not look (directly) at the Sun/wear eclipse glasses.
c
(Accept description of a procedure to make an image of the Sun on a screen.)
[1]
The result at 4 minutes/the 23°C result.
[1]
Does not fit the pattern/is anomalous.
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
6
CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 7
Answers
1
a
The species of leaf/the species of plant.
[1]
b This species of snail prefers to eat leaves of species B.
c
[1]
Repeat the experiment/have more than two containers each with a snail and
two leaves in it.
[1]
d They have rotted/been decayed by decomposers.
[2]
2
Bacterium and yeast
[2]
3
Orangutans, fruit bats, durian fruit, figs, clouded leopards and microorganisms
included in the food web.
[1]
Arrows connecting all organisms correctly and all of the five named species to
the microorganisms.
[1]
All arrows pointing in the correct direction.
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
7
CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 8
Answers
1
Iron filings heated with sulfur to produce iron sulfate.
2
a
[1]
Any three from:
Physical:
Soft grey solid
Dull surface
Cut surface is shiny
Melting point is 63.5°C
Chemical:
Cut surface does not stay shiny for long in air because it reacts with oxygen to
form an oxide.
Reacts violently with water and gives off hydrogen
Burns with a violet coloured flame
[3]
b Metal plus any reason from: shiny surface; reacts with oxygen rapidly; reacts with water
to produce hydrogen.
[1]
3
Filter paper, filter funnel, beaker, conical flask, test tube, universal indicator,
pipette. Allow variations if the equipment listed would work.
[2]
4
Hydrogen
[1]
5
a
Zinc chloride
[1]
b Sulfuric acid
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
8
CAMBRIDGE LOWER SECONDARY SCIENCE 7: END-OF-UNIT TEST ANSWERS
Unit 9
Answers
1
2
Electrons
[1]
b Negative
[1]
a
a
Insulator(s)
[1]
b Electrons are not free to move/are inhibited from moving
3
a
[1]
through/in paper
[1]
Circuit with cell, lamp and switch (open or closed)
[1]
No gaps in wires and no wires drawn into or through components
[1]
b Add another cell (in series)
c
4
[1]
Ammeter
[1]
High voltage/danger from electricity/danger of electric shock
[1]
[Total: 10 marks]
Cambridge Lower Secondary Science 7 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
9