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Energy flow
1.
The main reason why green plants cannot use nitrogen directly from the air is:
the triple bonds holding the nitrogen atoms together in the molecule require too much energy to break them
the nitrogen molecule is too unstable
nitrogen molecules are insoluble in water
nitrogen gas dissolves in water to produce a strongly acidic solution which would damage the plant cells
2.
In the carbon cycle, photosynthesis:
releases carbon dioxide from the oceans
releases carbon dioxide into the atmosphere
fixes carbon in carbonates
fixes carbon in biomass
3.
In the water cycle, photosynthesis:
converts glucose into water
converts liquid water into solid water
converts gaseous water to liquid water
fixes hydrogen from water into biomass
4.
Gross primary production is highest in:
a rainforest
prairie
tundra
a desert
5.
A system’s productivity is measured in:
kJ m
-2
yr
-1
kJ m
-1
yr
-1
kJ m s
-1
kJ m
-2
s
-1
6.
The rate at which energy from sunlight is made available to consumers by green plants is known as a system’s:
gross primary production
net primary production
productivity
growth rate
7.
In green plants, energy is stored mainly in:
glucose
ATP
starch
cellulose
8.
When light energy is absorbed by chlorophyll during photosynthesis:
chlorophyll combines with carbon dioxide to produce glucose
chlorophyll is converted to ATP
chlorophyll decomposes to form glucose and water
a high energy electron is released from the chlorophyll molecule
