Competition occurs when

The orchid $Ophrys$ employs 'sexual deceit' to get pollinated by a species of bee. One petal of its flower bears an uncanny resemblance to the female of the bee in size,colour,and markings. The male bee perceives it as the female and attempts to copulate with the flower. During this process,pollen grains are dusted on the male bee's body. What is this phenomenon called?

$A$ plant growing on another plant without drawing any nourishment is

Given below are two statements:
Statement-$I$: For plants,herbivores are the predators.
Statement-$II$: Nearly $25\%$ of all insects are known to be phytophagous.

Who proposed the Competitive Exclusion Principle?

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?