Question

Why photosynthesis is called an endothermic reaction?

Answer 1

it requires heat from sunlight to carry out the reaction. endothermic means that a reaction absorbs heat to take place.

Answer 2

endo means in and thermal means heat therefore any reaction that takes place in heat is called endothermic reaction
during photosynthesis sunlight ( heat) which is absorbed by chlorophyll along with water and nutrients to give glucose and oxygen as heat is taken in and not eliminated it can be called endothermic reaction