Commensalism can be represented as :

Herbivores,which are an integral part of the ecosystem's food chain,can be ecologically considered as:

Match the Column-$I$ with Column-$II$:

Column-$I$	Column-$II$
$(a)$ Parasitism	$(i)$ $++$
$(b)$ Commensalism	$(ii)$ $+-$
$(c)$ Amensalism	$(iii)$ $0+$
$(d)$ Mutualism	$(iv)$ $0-$

Statement $-I:$ The interaction where one species is benefitted and the other is neither benefitted nor harmed is called commensalism.
Statement $-II:$ Barnacles growing on the back of a whale is an example of commensalism.

Two closely related species competing for the same resources cannot coexist indefinitely. This principle is known as:

Monarch butterflies are highly distasteful to predators due to: