Page 22 - Science Coursebook

Unit 1 End of unit questions

1.1 a Copy and complete the word equation for photosynthesis.
carbon dioxide + ........................... → .............................. + .............................. [3]
b Explain how chlorophyll helps this reaction to happen. [2]

1.2 Carri tested a leaf for starch. The list of steps shows what she did, but they are
in the wrong order.
A Put iodine solution onto the leaf.
B Put the leaf into hot ethanol.
C Dip the leaf into water to soften it.
D Put the leaf into boiling water for five minutes.

a List the steps in the correct sequence. [1]
b Explain why Carri carried out step D. [2]
c Explain why Carri carried out step B. [2]

1.3 Yousef did an experiment to find out how giving plants different amounts of

water affected their growth.

Yousef sowed (planted) nine seeds, each in separate pots. He poured 20 cm of water into each pot,
3
to encourage the seeds to germinate. He left all the pots in the same place in the lab.

When all the seeds had germinated, Yousef separated the pots into three groups,
with three pots in each group. Each day, for seven days, he added a measured volume
of water to each pot.

Yousef measured the height of each seedling on day 1 and day 7. These are his results.

Group Seedling Height of seedling / mm Increase in
Day 1 Day 7 height / mm
A no water 1 6.0 6.5 0.5
2 5.5 6.0 0.5
3 5.5 6.0 0.5
B 2 cm water 4 5.5 7.5 2.0
3
5 6.0 8.0 2.0
6 6.0 8.5 2.5
C 5 cm water 7 6.0 9.5
3
8 5.5 9.5
9 6.0 10.0

a Calculate the increase in height for each of the seedlings 7, 8 and 9. [1]
b Calculate the mean increase in height for each group of seedlings. [2]
c On graph paper, draw a bar chart to show Yousef’s results. Put volume of
water on the x-axis, and mean increase in height on the y-axis. [4]
d Write a conclusion that Yousef could make from his results. [1]

20 1 Plants