Many parasites have evolved to be …$A$… in such a way that both host and the parasite tend to …$B$… that is, if the host evolves special mechanisms for rejecting or resisting the parasite, the parasite has to evolve mechanisms to …$C$… and neutralize them, in order to be successful with the same host species

Choose the correct option for $A , B$ and $C$

$A$ : An ecological niche is usually occupied by a single species.
$R$ : More than one species can live in same habitat.

What is a keystone species

The principle of competitive exclusion was stated by

Which of the following is an example of a defence used by plants against herbivores?

$I.$ Production of caffeine, tannin quinine

$II.$ More production of non-woody tissues

$III.$ Productions of hairs, thorns, spines

$IV.$ Production of hormone-like chemicals that interfere with insect metamorphosis

Select the correct pair