The interaction between "Cuckoo and Crow" is an example of:

Examples of chemicals produced by plants as a defense against grazers and browsers:
$I.$ Nicotine
$II.$ Caffeine
$III.$ Quinine
$IV.$ Strychnine
$V.$ Opium
Choose the correct combination.

Two butterfly species are competing for the same nectar of a flower in a garden. To survive and coexist together,they may avoid competition in the same garden by:

Match the following columns:

Column-$I$	Column-$II$
$P$. Calotropis	$I$. Special chemical
$Q$. Cactus and Acacia	$II$. Camouflage
$R$. Monarch butterfly	$III$. Thorns
$S$. Some species of insects and frogs	$IV$. Glycosides

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

Choose the correct group for commensalism from the following:
$(a)$ The cattle egret and grazing cattle
$(b)$ Barnacle balanus and Barnacle chathamalus
$(c)$ Goat and Abingdon turtle from Galapagos island
$(d)$ Barnacles growing on the back of whale