Match the columns:

Column-$I$	Column-$II$
$(a)$ Predation	$(i)$ Cuscuta and hedge plant
$(b)$ Commensalism	$(ii)$ Balanus and Chathamalus
$(c)$ Parasitism	$(iii)$ Cactus and Moth
$(d)$ Competition	$(iv)$ Orchid and Mango

Whose field experiment showed that on the rocky sea coast, the larger and competitively superior barnacle excludes the smaller barnacle?

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 $C$.

What did Gause demonstrate regarding ecology and competition?

In a stable population,what is the ecological role of predation?

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.