The callus is a mass of undifferentiated cells that produce at the wound edge. It is induced to differentiate by varying the ratio of hormone auxin and cytokinin in the medium. If the callus is transferred to the medium with a high concentration of cytokinin and low concentration of auxin that leads to the development of shoot and if callus is transferred to the medium with a high concentration of auxin and less concentration of cytokinin that leads to the development of roots.