Define ectoparasite and endoparasite and give suitable examples.

What happens when the number of organisms increases in a specific area?

Given below are two statements:
Statement $I$: Gause's competitive exclusion principle states that two closely related species competing for different resources cannot exist indefinitely.
Statement $II$: According to Gause's principle,during competition,the inferior will be eliminated. This may be true if resources are limiting.
In the light of the above statements,choose the correct answer from the options given below :

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 $C$.

Refer to the given table that summarizes the interactions between two organisms (organism $1$ and organism $2$). Identify the types of interaction ($A, B$,and $C$) and select the correct answer.

Effects on Organism $1$	Effects on Organism $2$ (Benefit,Harm,No Effect)
Benefit	Mutualism,Predation,$B$
Harm	$A$,Competition,Amensalism
No Effect	Commensalism,$C$,$-$

$(i)$ $A$ can be either predation or parasitism.
$(ii)$ $B$ can be either commensalism or amensalism.
$(iii)$ $C$ can be amensalism.
$(iv)$ $A$ can be amensalism.

In an association of two animal species,one is a termite which feeds on wood and the other is a protozoan $Trichonympha$ present in the gut of the termite. What type of association do they establish?