Ecosystems — BIOLOGY STD 12 Science — Question

1. Always upright

Explanation:

Pyramid of energy is always upright, can never be inverted, because the energy always flows from a particular trophic level to the next trophic level. The amount of available energy decreases during transfer from one trophic level to another. So, as we go from the first trophic level to the top trophic level, the amount of available energy becomes less and less.