For cryopreservation,plant materials are frozen at (in $^{\circ} C$)

The pioneer worker in plant tissue culture is:

Identify the incorrect statements from the following:
$(i)$ Callus is obtained in $2$ to $3$ weeks.
$(ii)$ Suspension culture does not show faster growth compared to callus culture.
$(iii)$ Orchid seeds do not contain stored food.
$(iv)$ $2,4-D$ is used only in callus culture.

What is meant by totipotency?

Arrange the following steps of somatic hybridisation in a correct sequence.
$A$. Digestion of cell walls.
$B$. Isolation of naked protoplasts.
$C$. Fusion of protoplasts to get hybrid protoplast.
$D$. Isolation of single cells from two different varieties of plants.
$E$. Growing of hybrid protoplast to form a new plant.
Choose the correct answer from the options given below:

Which of the following enhances or induces fusion of protoplasts?