What does the following figure represent?

Which of the following is an example of a positive interaction in a population?

Identify the correct statement/s from the following:
$I$. $Cuscuta$ is a chlorophyllous endoparasite.
$II$. The human liverfluke needs only one host to complete its life cycle.
$III$. The life cycle of endoparasite is more complex due to their extreme specialisation.
$IV$. During the course of evolution the host bird's eggs have evolved to resemble the eggs of the parasitic bird.

Name important defence mechanisms in plants against herbivory.

Which one of the following population interactions is widely used in medical science for the production of antibiotics?

Find the odd one out,according to parasitism.