The principle of competitive exclusion was stated by

An association of two species where both the partners derive mutual benefit from each other is

$I.$ Some species of insects and frogs are critically coloured (camouflaged)

$II.$ Some animals are poisonous

$III.$ Monarch butterfly are distasteful

The above adaptations are against

Animals eating plants are categorised separately as ...$A$..., they are in a broad ecological context, not very different from ...$B$...

Choose the correct option $A$ and $B$

In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gause’s Principle, one of the species is to be eliminated in due course of time, but both are surviving well in the aquarium. Give possible reasons.

Select the statement which explains best parasitism.