Biomass is the total mass of organisms at a trophic level.
Each of the steps in the food chain is a trophic level .
Biomass is the total mass of organisms at a step in the food chain.
Biomass is the total mass of organisms at a step in the what?

1) Energy
2) Plants growth
3) food chain
4) agriculture
5) Animal survival
6) Energy.
7) energy usage
8) kinetic energy