Environmental Science Ecosystems and Ecology 3

Question 1

What is the term for the total mass of living organisms in a given area or trophic level?

Accepted Answer

Biomass

Answer

Biomass refers to the total mass of living biological organisms in a particular area or ecosystem.

Question 2

Which process removes dissolved oxygen from water, harming aquatic life, often caused by excess nutrient runoff?

Accepted Answer

Eutrophication

Answer

Eutrophication occurs when nutrient overload triggers algal blooms that deplete oxygen as they decompose.

Question 3

The competitive exclusion principle states that two species competing for identical resources cannot:

Accepted Answer

Coexist indefinitely

Answer

Gause's principle holds that two species with the same niche cannot coexist; one will outcompete the other.

Question 4

Which term describes a species native and restricted to a particular geographic area?

Accepted Answer

Endemic

Answer

Endemic species are found exclusively in a specific location and evolved in that area.

Question 5

What is net primary productivity (NPP)?

Accepted Answer

Total photosynthesis minus plant respiration

Answer

NPP is gross primary productivity minus the energy plants use for their own respiration, representing available organic matter.

Environmental Science Practice Test