Q.What do you mean by embryoids ?

Embryoids are somatic embryos -- bipolar, embryo-like structures formed in culture from non-zygotic (somatic) cells, without fertilisation, that can germinate into complete plants and are used to make artificial seeds.

In plant tissue culture, certain totipotent somatic cells (often within an embryogenic callus, or sometimes single cells in suspension culture) can be induced, by an appropriate balance of plant growth regulators (typically a high auxin, e.g. 2,4-D, phase followed by its withdrawal), to undergo a process called somatic embryogenesis. The resulting structures are called embryoids: they are not formed by the fusion of male and female gametes, yet they closely mimic true zygotic embryo development, passing through the same recognisable globular, heart-shaped, torpedo, and cotyledonary stages, and they are bipolar -- possessing distinct root and shoot poles -- unlike an organised but unipolar callus-derived shoot bud. Because an embryoid can germinate directly into a complete, normal plantlet (with both root and shoot already established) without needing a separate rooting step, embryoids are of great …