CAMBRIDGE PRIMARY SCIENCE 6: TEACHER’S RESOURCE
Workbook answers
Unit 1 The human body
d
Yes. The measurement for digging. The
pulse rate measured is low although he is
doing a physical activity. We would expect
the measurement to be higher.
He should do all the activities for the
same length of time, then measure his
pulse rate. He should also start each
activity after a period of rest (sitting still)
to allow his heartbeat to return to normal.
Topic 1.1: The circulatory system
Focus
1
Heart, blood and blood vessels (in any order)
2
a
The heart pumps blood through the body.
b
The left side of the heart pumps blood
that contains oxygen.
c
The right side of the heart pumps blood
without oxygen to the lungs.
d
Blood is carried in the blood vessels.
e
Blood carries food and oxygen to all
parts of the body and takes away waste
products.
a
d
b
e
B
B
C
C
c
A
a
160
1
Bar chart of pulse rates
after different activities
Heartbeats per minute
140
120
100
2
60
40
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1
Marcus’s pulse rate would increase. The
more active you are, i.e. pedalling faster,
the more often your heart must beat to
carry enough food and oxygen from the
blood to your muscles.
We breathe in air through our nose or mouth.
The air we breathe in contains oxygen gas.
The air moves down the windpipe and into
our lungs. The oxygen in the air then moves
from the lungs into the blood. We breathe out
air that contains carbon dioxide gas. The ribs
protect our respiratory system.
air enters
the nose
air moves
down windpipe
into lungs
20
lungs fill
with air
sit
c
g
Practice
80
0
b
Body activity/exercise makes the pulse
rate increase.
Focus
Challenge
4
f
Topic 1.2: The respiratory system
Practice
3
e
Marcus’s pulse rate was lowest when he
was sitting still. The body needs less food
and oxygen when it is still or inactive, so
the heart does not have to beat fast.
diaphragm
moves
downwards
3
Nose and mouth → windpipe → lungs → blood
Playing football
Cambridge Primary Science – Baxter & Dilley © Cambridge University Press 2021