describe the stages in embryo development in dicot plant

Mostly the zygote develops only after certain amount of  endosperm is formed to ensure that nutrition will be provided for the developing embryo.

the embryo develops at the micropylar end of the ovule.

Dicot plants have 2 cotyledons and an embryoal axis.

the portion above the cotyledons is called the epicotyl it terminates with the plumule

the portion below the cotyledons is called the hypocotyl and terminates with the radicle and root cap

note: after the embryo develops the root grows towards the micropylar end while the plumule grows towards the chalazal end