Question

Cellular Totipotency means
(a) Synthesis of new cells
(b) Formation of new species
(c) Formation of new plants
(d) The capability of a plant cell to form a complete plant

Answer 1

Hint: Cellular totipotency is an ability seen in plant cells and some animal cells. Totipotent cells can differentiate into any embryonic or extraembryonic cells.

Complete answer:
Cellular Totipotency is the ability of a single cell to differentiate into all cell types and to organize them to give rise to an entire organism in a suitable culture medium with appropriate temperature and aeration. Spores and zygotes are some of the examples of totipotent cells. Every plant cell containing complete genetic information shows cellular totipotency, that is, they are capable of giving rise to an entirely new plant. Totipotency is derived from Latin “Totipotential” meaning “ability for all things In the spectrum of cell potency, totipotency represents the cells with the greatest potential of differentiation, being able to differentiate into any embryonic cells or extraembryonic cells as well.
When a piece of differentiated tissue from a plant is cultured on a suitable nutrient medium, the mature, differentiated cells undergo dedifferentiation to transform back into meristematic cells. These dividing cells of callus then undergo re-differentiation to form an entirely new plant, provided the suitable nutritional and hormonal requirements are fulfilled.
These two features of dedifferentiation and redifferentiation are inherently characteristic to plants and are the rationale behind the phenomenon of totipotency which forms the basis of plant tissue culture.
So the answer is ‘Capability of a plant cell to form a complete plant’.

Note: Pluripotent cells can differentiate into embryonic cells only and unipotency is the concept that one stem cell can differentiate into a single cell type only. Multipotency is the ability of cells to differentiate into a discrete type of cells.