Observe the set of $4$ figures $A$,$B$,$C$ and $D$ and answer the following questions:
$(i)$ Which one of the figures shows mutualism?
$(ii)$ What kind of association is shown in $D$?
$(iii)$ Name the organisms and the association in $C$.
$(iv)$ What role is the insect performing in $B$?

Small fish get stuck near the bottom of a shark and derive their nutrition from it. This kind of association is called as:

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

Some species of insects and frogs are ....... to avoid being easily detected by the predator.

Identify the correct statement/s from the following:
$I$. $Cuscuta$ is a chlorophyllous endoparasite.
$II$. The human liverfluke needs only one host to complete its life cycle.
$III$. The life cycle of endoparasite is more complex due to their extreme specialisation.
$IV$. During the course of evolution the host bird's eggs have evolved to resemble the eggs of the parasitic bird.

$A$ cuckoo laying eggs in the nest of other species of birds is an example of