Photosynthesis! please help!?

Question

A pot of plant was kept in the dark for 24 hours. After taking it out from the dark, the plant was watered and a black piece of paper was taped on one of its leaves. the potted plant was then placed under sunlight for a few hours. The leaf with the black paper was plucked off the plant and the black paper was removed.the leaf was then prepared and tested for starch using iodine solution.

a.) what was the purpose of keeping the plant in the dark for 24 hours first?

b.)what would be observed when the leaf was tested for starch?

c.) explain the observation.

Answer 1

Basically, this experiment proves sunlight to be a vital need for photosynthesis.the plant was kept in the dark so that it would use up the stored starch so that none of the starch reacts with iodine in the region covered with black tape n it ensures that the black blue color got wen iodine reacts with starch is only bcos of the starch freshly produced by the plant wen kept in sunlight again.so wat happens is thatthe plant uses all the stored starch wen kept in dark for a day.then it is taped (a portion that is) to check whther that region produces starch or not,that is phtsynth is carried out in the absence of sunlight or not.the leaf wen treated with iodine shows the covered region to be pale n the rest to be blue black.this shows that starch produxn n photosynth. occurs only in the presence of sunlight

Answer 2

a) The plant was put into the room to create a control, by putting this plant in to a black room it stops photosynthesis.

b) Testing the plant for starches was looking for more glucose in the tested leaf.

c) This experiment tests whether or not glucose builds up over time with out photosynthesis.