AP BIOLOGY

Detailed explanation-1: -Differential concentration of auxin and cytokinin regulates morphogenesis. So, callus tissue can be regenerated into plantelets by altering concentration of hormones.

Detailed explanation-2: -Callus Induction by Plant Hormones. Auxin and cytokinin have been widely used to generate callus, but surprisingly little is known about how they induce callus at the molecular level.

Detailed explanation-3: -Thus, callus cultures are basically clumps of cells raised due to disorganized proliferation of cells from the segment of plant organs. In this technique plant cells propagate on suitable media to form clumps of undifferentiated cells called callus.

Detailed explanation-4: -The plant hormones auxin and cytokinin are critical for plant regeneration in tissue culture, with cytokinin playing an instrumental role in shoot organogenesis.

Detailed explanation-5: -A callus is a mass of irregular, undifferentiated, parenchymatous and totipotent cells. These cells have the ability to divide and differentiate to form an entire organism. It is formed in culture media due to active mitotic divisions of the cells of the explant (plant part, tissue or cell being cultured).