Question

why do insectivorous plant need to feed on insects when they can synthesise their food?

Answer 1

Answer:

The insectivorous plants grow in soil which do not contain sufficient nitrogen mineral. These plants (e.g. pitcher plant) are green and carry out photosynthesis to obtain a part of the food required by them. ... So, insectivorous or carnivorous plants feed on insects to obtain the nitrogen needed for their growth.