Definition / Explanation: Ectoparasites

In the early $1920$s,the prickly pear cactus introduced into Australia caused havoc by spreading rapidly into millions of hectares of rangeland. Finally,how was it controlled?

Lianas are vascular plants rooted in the ground and maintain erectness of their stem by making use of other trees for support. They do not maintain direct physiological relation with those trees. Discuss the type of association the lianas have with the trees.

In a humid climate,the presence of spines in shrubs is primarily:

Choose the correct option for population interaction.

$A$ : The interaction between sea anemone and clown fish is commensalism.
$R$ : The fish gets protection from predators but anemone does not appear to derive any benefit.