(N/A) An embryo develops at the micropylar end of the embryo sac where the zygote is situated. Most zygotes divide only after a certain amount of endosperm is formed. This is an adaptation to provide assured nutrition to the developing embryo.
Although seeds differ greatly,the early stages of embryo development are similar in both monocotyledons and dicotyledons.
The zygote gives rise to the proembryo and subsequently to the globular,heart-shaped,and mature embryo.
Typical dicot embryo: $A$ typical dicotyledonous embryo consists of an embryonal axis and two cotyledons. The portion of the embryonal axis above the level of cotyledons is the epicotyl,which terminates with the plumule or stem tip. The cylindrical portion below the level of cotyledons is the hypocotyl,which terminates at its lower end in the radicle or root tip. The root tip is covered with a root cap.
Embryo of monocotyledons: Embryos of monocotyledons possess only one cotyledon. In the grass family,the cotyledon is called the scutellum,which is situated towards one side (lateral) of the embryonal axis. At its lower end,the embryonal axis has the radicle and root cap enclosed in an undifferentiated sheath called the coleorrhiza. The portion of the embryonal axis above the level of attachment of the scutellum is the epicotyl.
The epicotyl has a shoot apex and a few leaf primordia enclosed in a hollow foliar structure called the coleoptile.