Question

A culture medium having callus grown from tobacco pith, is supplied with more of cytokinins than auxins. It will result in the development of (a) tap root (b) Shoot bud (c) bulbil (d) flower bud.

Answer 1

The callus is like a cancerous tumor, where the cells are undifferentiated. If the concentration of auxin with respect to that of cytokinin ratio is changed, the cells of the callus undergo transformation to produce organs like roots or shoots. If the ratio between auxin and cytokinin is high, the callus cells undergo transformation and produce roots. On the other hand, if the ratio between auxin and cytokinin is low the callus cells initiate shoots.

High concentrations of cytokinin generally inhibit or delay root formation and also prevent root growth.

High levels of cytokinin usually cause many small shoots to be produced, which typically fail to elongate and cause the leaves of some species to have an unusual shapes.

Hence, it will result in the development of Shoot bud.