How many types of plant tissue culture are there?

Haploid plants are obtained from which of the following?

Which of the following is $NOT$ an objective of embryo culture?

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 growth regulators are used in the medium during callus culture?

Virus-free plants can be generated through-