Organisms at each trophic level depend on those at the lower level trophic level for their energy demands except:

1.	Primary consumers	2.	Secondary consumers
3.	Tertiary consumers	4.	Decomposers

Each trophic level has a certain mass of living material at a particular time, best called as:

Approximately, what percent of energy is transferred to each trophic level from the lower trophic level in an ecosystem?

Identify the correct statements: 

The pyramid of biomass in the sea is generally inverted because:

Which of the following pyramids can never be inverted in any ecosystem?
1. Pyramid of numbers
2. Pyramid of biomass
3. Pyramid of energy
4. All ecological pyramids can be inverted

In an ecological pyramid, the saprotrophs:
1. are primary producers
2. can be at any trophic level
3. are not given any place
4. are kept with apex predators

Ecological succession is:
1. gradual and predictable
2. gradual and unpredictable
3. sudden and predictable
4. sudden and unpredictable

The entire sequence of communities that successively change in a given area are called:
1. Taxa
2. Seres
3. Pioneers
4. Climax

Ecological succession has paralleled:
1. Glaciations
2. Mass extinctions
3. Genetic drifts
4. Evolution