Question

Callus is
a) tissue that forms the embryo
b) an insoluble carbohydrate
c)tissue that grows to form embryoid
d) unorganized actively dividing mass of cells maintained in culture

Answer 1

Hint: Callus is the mass of the cell which grows from the cut or a wounded part of the plant. Callus usually arises from the cambium region of the plant. The callus may help in giving rise to the new plant.

Complete answer:
The callus is the mass of the cell which actively divides to form the mass of the cell or the callus is the unorganized actively dividing the mass of cells maintained in culture. The growth of the callus occurs where there is a huge amount of cytoplasm present which helps in triggering the cell division. The growth hormones also act on it to help it in differentiation. Callus can give rise to new plants by giving rise to roots and stem from them. If a plant has a callus developed it is possible to develop a new plant body from that part. In culture, if the callus is treated with growth hormones then it would give rise to the shoot and root part of the plant. Auxin treatment would help in the formation of roots and shoots whereas cytokinin treatment would help in its growth, differentiation, and maturation. In the culture, the callus is taken from the explanations and the growth of the plant from this culture is different from that of the one which is produced by the wound on the plant.
So, the answer is ‘unorganized actively dividing mass of cells maintained in culture’.

Note: To grow a callus structure successfully one must keep three things in mind which are aseptic plant material preparation, the supply of the suitable amount of nutrients like auxin and cytokinin, and the last thing is the incubation which needs to be done in the controlled conditions.