Topic 12

Question 1

what is an ecosystem?

Answer 1

communities of organisms interacting with their physical environment under the influence of environmental factors

Question 2

what is ecosystem energetics?

Answer 2

the study of how energy is fixed by autotrophs and made available to heterotrophs

Question 3

what are heterotrophs?

Answer 3

consummers

Question 4

what are autotrophs?

Answer 4

producers

Question 5

what is energy measured as?

Answer 5

The dry weight of organic matter in an
organism or ecosystem (tonnes C km -2)

Question 6

what is the first trophic level?

Answer 6

primary producers

Question 7

what is primary productivity?

Answer 7

The rate at which energy is fixed

Question 8

what do primary producers carry out?

Answer 8

primary production

Question 9

what do primary producers do?

Answer 9

fix inorganic nutrients into organic molecules

Question 10

what is gross primary production?

Answer 10

total amount energy fixed into organic
molecules in an ecosystem

Question 11

what is net primary production?

Answer 11

What the producer makes, minus what the
producer uses for itself
– The amount of energy for growth (Eproduction)

Question 12

what is net primary production measured as?

Answer 12

biomass

Question 13

what does net primary production tell us?

Answer 13

how much energy is available to other trophic levels

Question 14

what are primary consumers?

Answer 14

herbivors

Question 15

what trophic level are primary consumers?

Answer 15

second

Question 16

what type of organism are primary consumers?

Answer 16

herbivores

Question 17

what are primary consumers?

Answer 17

Organisms that consume the organic molecules of primary producers

Question 18

what do primary consumers use to support their energy budget?

Answer 18

the energy consumed

Question 19

what happens to the excess energy consumed in primary consumers?

Answer 19

its turned into new biomass

Question 20

what is biomass production in the second trophic level called?

Answer 20

secondary production

Question 21

what type of organism are tertiary consumers?

Answer 21

omnivores and carnivors

Question 22

what trophic level are tertiary and secondary consumers on?

Answer 22

third and fourth

Question 23

what are tertiary consumers?

Answer 23

Organisms that consume the organic molecules of consumers in a lower
trophic level

Question 24

how do tertiary consumers support their energy budget?

Answer 24

they use the energy consumed

Question 25

what is biomass production on the third and fourth trophic levels called?

Answer 25

secondary production

Question 26

what are decomposers and detritivores?

Answer 26

Organisms that consume the dead
organic matter of primary producers, primary consumers

Question 27

what do decomposers/ detritivores do?

Answer 27

cycle nutrients

Question 28

what is the biomass production of decomposers?

Answer 28

secondary production