Some plants have a habit of harbouring ants to save themselves from damage by other animals,which is known as:

Which of the following characteristics is described by Gause's competitive exclusion principle?

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

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

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

Column-$I$	Column-$II$
$(P)$ Lichens	$(i)$ Parasitism
$(Q)$ Abingdon tortoise and goat	$(ii)$ Commensalism
$(R)$ Sea anemone and clown fish	$(iii)$ Competition
$(S)$ Human and liver fluke	$(iv)$ Mutualism

Interspecific interactions arise from the interaction of

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Abingdon tortoise in Galapagos islands became extinct within a decade after goats were introduced.
Reason $R$: Goats were more efficient at browsing than Abingdon tortoise.
In the light of the above statements, choose the most appropriate answer from the options given below: