Question

in black paper experiment why the plant in dark first and in sunlight​

Answer 1

Please specify the question more accurately.

Answer 2

Answer:

Iodine test in the black paper uncovered region show a positive result for the presence of starch i.e iodine in this region turns into blue-black color. The reason for this is that uncovered region gets sunlight and so this part of the leaf is able to synthesize starch