Question

Prove with experiment that light is necessary for photosynthesis? 

Answer 1

i) De-starch a potted plant by keeping it in dark for two days.

ii) Then transfer it to light and select two leaves of this plant for experiment

iii) Now wrap one by black paper.

iv) Wrap other by black paper but a L shaped part of the paper is cut out so

that light can pass from here.

v) Now put the potted plant to light for 6 hours

vi) It will observe that leaf which did not receive any light is free of starch

and brown. 

vii) Second leaf light could pass through L shaped area. Only this area turn

dark blue while other part remain brown.

viii) This shows that light is necessary for photosynthesis.