Question

A leaf from a potato plant that was left in sunlight is tested for starch using iodine solution. The leaf turns a blue–black colour, indicating the presence of starch. The same plant is then left in the dark for 24 hours, and a leaf is tested. This time there is no starch. Potatoes attached to the roots of the plant are tested with iodine and do contain starch.

Explain how a potato plant transports materials so that starch is removed from the leaves and builds up in the storage organs.

Answer 1

After that the starch has been produced photosynthesis, the latter is transported by the process, translocation, which is movement of food substances, towards the potatoes which are the storage organs through the phloem vessels.