Which kind of relationship is seen between a mango tree and an orchid that grows on the branch of the mango tree?

Barnacles growing on the back of a whale is an example of .........

Consider the following four statements and select the option which includes all the correct ones $:-$
$(a)$ Sparrow eating any seed is no less a predator.
$(b)$ Monarch butterfly is highly distasteful to its predator.
$(c)$ Nearly $25 \%$ of all insects are known to be phytophagous.
$(d)$ Thorns are the most common morphological defence mechanism.
Options $:-$

Which of the following is not a defence evolved by a prey to avoid predators?

What type of relationship is observed between insect-pollinated flowers and their pollinators?

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