Q.The selected tissue to establish a new plant in a culture medium :

The explant is the piece of living plant tissue selected to start a tissue culture.

In plant tissue culture, the process begins by surface-sterilising and excising a small piece of tissue -- the explant -- from a healthy donor plant; common explant sources include shoot tips, axillary buds, leaf segments, root tips and anthers, chosen because they contain actively dividing or totipotent cells capable of dedifferentiation. This explant is inoculated onto a nutrient medium (such as Murashige and Skoog medium) supplemented with the appropriate balance of auxins and cytokinins, where its cells dedifferentiate and proliferate into an unorganised, undifferentiated mass of cells called callus. Depending on the hormonal regime and species, the callus can be induced to redifferentiate either organogenically (forming shoots and roots separately) or, in some species, through somatic embryogenesis, producing embryo-like structures called embryoids that mimic the stages of zygotic embryo development. These embryoids, or organogeni …