Give reason-?

Question

1)the potato tuber is a stem modification,but the sweet potato is a root modification.
2)The bulb is described as an organ of both perennation and vegetative propation.

Answer 1

A tuber, or stem tuber, is a development of a stolon, or above-ground rhizome, thickened for use as a storage organ. The tuber usually, though not always, develops when the stolon becomes subterranean, such as in a potato. This modified stem forms at the end of a lateral branch. Auxiliary buds are located at the nodes. When the buds develop, adventitious roots and rhizomes form below them.

The part of the sweet potato that is eaten is the tuberous root (as opposed to the tuber of the white potato). Because the sweet potato is a root, it lacks "eyes" or buds on the outer surface. Sweet potatoes have orange flesh with a high sugar content. The skin is orange to brown, and the ends of the tuberous roots are pointed.

Both types of tuber can give rise to new individuals and so provide a means of vegetative reproduction.

The bulb --- A modified stem forms the base of the bulb, and plant growth occurs from this basal plate. Roots emerge from the underside of the base, and new stems and leaves from the upper side.so it is described as an organ of both penetration and vegetative propagation.