Question

If a leaf of a destarched plant is covered with a black paper only on the upper side facing the sun, then will the leaf still absorb light energy??

Answer 1

The black paper strip should be attached tightly on both sides of leaf so that no sunlight enters in covered portion of leaf.
When partially covered leaf is treated with iodine solution then the covered portion do not turn blue-black on adding icdine solution where as the uncovered portion which received the light turns blue-black due to synthesis of starch in them.