Question

Trace the development of embryo after syngamy in a dicot plant.

Answer 1

1. The zygote generally begins dividing after some endosperm has formed, ensuring nutrition for the embryo.
2. The first transverse division forms a terminal cell and a basal cell. The basal cell produces the suspensor; the terminal cell forms the embryo proper.
3. The embryo proper divides repeatedly, passing through proembryo, globular and heart-shaped stages.
4. The two cotyledon primordia form, and the embryo differentiates into an embryonal axis with plumule, epicotyl, hypocotyl and radicle.
5. The suspensor pushes the developing embryo into the endosperm and later degenerates. The mature dicot embryo has two cotyledons.