The best source of energy in the environment is

The correct path of energy flow in an ecosystem is

In an aquatic ecosystem, which type of food chain is the major conduit for energy flow?

$10 \%$ law of energy transfer was given by

Assertion $A$: Heat energy is available for the functioning of a system.
Reason $R$: Some amount of energy is lost during energy transformation.
Which option is correct for Assertion $A$ and Reason $R$?

The transfer of energy from one trophic level to another occurs according to the second law of thermodynamics. What is the average efficiency of energy transfer from herbivores to carnivores (in $\%$)?