Page 45 - 新思维科学学生用书9 样章

1 Photosynthesis and the carbon cycle

a What yield of grain did the farmer get when she did not add any fertiliser? [1]

b The farmer decided that there was no need to add more than about 60 kg
of fertiliser per hectare. Explain how the results of the experiment support
her decision. (Remember that fertiliser is expensive.) [2]
c Explain why the yield of grain increases when nitrate-containing fertiliser

is added. [2]
d Suggest why the results of this experiment might be different if it was
repeated in a different place. [2]
e Name one mineral, other than nitrate, that plants need for healthy growth.

Explain why they need this mineral. [2]
1.4 The diagram shows the carbon cycle.

A
2 1 1

D respiration

respiration
coal C B

3
gasolene gas

urine,
death and faeces,
long-term death
subjection to
high pressures
and temperatures

a Match each of these labels to the correct letter on the diagram.
i carbon in fossil fuels
ii carbon compounds in plants
iii carbon dioxide in the air

iv carbon compounds in animals [3]

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