In an association of two animal species, one is a termite which feeds on wood and the other is a protozoan Trichonympha present in the gut of the termite. What type of association they establish ?

Commensalism is the interaction in which

$A$ : Cattle or goat never graze on Calotropis.
$R$ : Thorns are present as a morphological means of defence

While living in and on the host species, the animal parasite has evolved certain adaptations. Describe these adaptations with examples.

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