The primary consumers in a pond ecosystem are
Phytoplankton
Zooplankton
Fishes
Bacteria
Flow of energy declines from low to higher trophic level in ecosystem, is mainly explained by
The second trophic level in a lake is
Whale is
Fill in the trophic levels $(1, 2, 3$ and $4)$ in the boxes provided in the figure.
The phytoplankton in the ponds act as