The flow of energy in an ecosystem is :
Bidirectional.
Unidirectional.
Both a and b.
None of these.
Biomass remaining after meeting the cost of respiration of producers is known as :
Gross productivity.
Primary productivity.
Net productivity.
Secondary productivity.
The amount of living matter at different trophic levels in an ecosystem at a given time is called :
Trophic level.
Standing crops.
Standing state.
All of these.
