Ecosystems and the Biosphere

Question 1

Energy flow through an ecosystem

Answer 1

It is linear, from the sun to producer to consumer to decomposer. Much of this energy is converted to heat as it moves from one organism to another, so organisms occupying the next throphic level cannot use it.

Question 2

Ecological pyramids

Answer 2

They typically express the progressive reduction in numbers of organisms, biomass, and energy found in successive trophic levels.

Question 3

Gross primary productivity (GPP)

Answer 3

In an ecosystem is the rate at which photosynthesis captures energy.

Question 4

Net primary productivity (NPP)

Answer 4

It is the energy that remains (as biomass) after plants and other producers carry out cellular respiration.

Question 5

Carbon cycle

Answer 5

It enters plants as CO2. Cellular respiration, combustion and erosion return CO2 to the water and atmosphere.

Question 6

Nitrogen cycle

Answer 6

It has 5 steps.

1) Nitrogen fixation
2) Nitrification
3) Assimilation
4) Ammonification
5) Denitrification

Question 7

Phosphorus cycle

Answer 7

It has no important gaseous compounds. Phosphorus erodes from rock as inorganic phosphate, which is absorbed by plants an animals. Decomposers release inorganic phosphate to the environment.

Question 8

Coriolis effect

Answer 8

The tendency of moving air or water, because of Earth´s rotation, to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.