Which of the following are always at the second trophic level of food chains?

In the food chain
Grass $\rightarrow$ Deer $\rightarrow$ Lion
operating in a forest,what will happen if all the
$(a)$ lions are removed?
$(b)$ deers are removed?

In the given figure,the various trophic levels are shown in a pyramid. At which trophic level is maximum energy available?

What type of biological components are herbivores?

$15 \%$ can be taken as the average value for the amount of organic matter that is present at each step and reaches the next level of consumers.

Which of the following organisms forms the first trophic level of a food chain?