CAMBRIDGE LOWER SECONDARY SCIENCE 8: MID-POINT TEST: UNITS 1 AND 4
Name ___________________________________
Date _____________
Disclaimer: This test and mark scheme have been written by the authors.
Mid-point test: Units 1 and 4
1
2
Draw a line from each structure in the respiratory system to its function.
[4]
structure
function
diaphragm
where gas exchange happens
alveolus (air sac)
a tube that carries air through the neck
bronchus
has muscles that contract which
causes you to breathe in
trachea (windpipe)
one of two tubes that carry air into the left
and right lungs
The table shows the body masses of six mammals. It also shows the total surface area of the
air sacs (alveoli) in the animals’ lungs.
Mammal
human
80 000
mouse
20
rabbit
rat
a
Body mass in g
1000
300
Total surface area of air sacs in m2
70
0.1
2
0.8
sheep
68 000
60
fox
20 000
40
The entries in the table are not in the best order.
Cambridge Lower Secondary Science 8 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
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CAMBRIDGE LOWER SECONDARY SCIENCE 8: MID-POINT TEST: UNITS 1 AND 4
Complete the table below by reorganising the entries so that it is easier to see
a pattern in the data.
Mammal
[2]
Body mass in g
Total surface area
of air sacs in m2
mouse
20
0.1
rat
300
0.8
rabbit
1000
2
fox
20000
40
sheep
68000
60
human
80 000
70
b Complete the sentence to describe the relationship between body mass and total
surface area of air sacs.
c
As total body mass increases, _______________________________________________.
the total surface area of air sacs increases
[1]
Suggest an explanation for the relationship you described in your answer to part b.
[2]
The greater the total body mass, means the body size is larger. As the body size is
_______________________________________________________________________________
large, it need more alveoli, where gas exchange occur at, to allowed all the cells to
_______________________________________________________________________________
respire with enough oxygen. Therefore, as total body mass increases, the total
surface area of air sacs increases.
_______________________________________________________________________________
3
In the United Arab Emirates, the desert is an important ecosystem.
a
Explain what is meant by the word ecosystem.
[2]
Ecosystem means the interactions between non-living things and living things in
_______________________________________________________________________________
a certain habitat.
_______________________________________________________________________________
_______________________________________________________________________________
Cambridge Lower Secondary Science 8 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
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CAMBRIDGE LOWER SECONDARY SCIENCE 8: MID-POINT TEST: UNITS 1 AND 4
b The desert provides many different places for organisms to live.
Which scientific term is used to describe the place where an organism lives?
Circle the correct answer.
environment
c
[1]
habitat
home
Camels, oryx and gazelles are herbivores that live in the desert in the United Arab Emirates.
Scientists wanted to find out how different herbivores affect the plants growing in the desert.
They counted the plants in two areas of desert.
In area P, there were camels, but no oryx or gazelles.
In area Q, there were oryx and gazelles, but no camels.
The table shows their results.
number of plants
number of different species of plants
Area P
Area Q
64
87
4
5
Evaluate the data – is there a conclusion that the scientists can make from their results?
[1]
No, because different species of animals can consume different species of plants,
and the amount of animals and plants there can be different and there can also be
_______________________________________________________________________________
other animals living in the same habitat, and the results didn’t show the left over
_______________________________________________________________________________
plants after a period of time.
d Prickly pear plants have been introduced into the United Arab Emirates.
These plants come from South America. They are adapted to grow in deserts.
Describe how the introduction of prickly pear plants could affect other organisms
in the deserts in the United Arab Emirates.
[2]
The
prickly pear plants can competite with the other plants to get minerals, the
_______________________________________________________________________________
population of other plants may decrease a bit and the population of the herbivores
_______________________________________________________________________________
will
increase because they have more food a bit.
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
Cambridge Lower Secondary Science 8 – Mary Jones, Diane Fellowes-Freeman and Michael Smyth © Cambridge University Press 2021
3