In viviparous animals, the young animal's earliest stages in the mother's body
A rudimentary plant contained in the seed.
In the reproductive cycle, the stage after the fertilization of the egg that precedes the development into a fetus.
The beginning; the first stage of anything.
In humans, usually the cell growth up to the end of the seventh week in the mother's body
An organism in the earlier stages of development before it emerges from the egg, or before metamorphosis.
An immature ovum in mammals.
The structure in a plant that develops into a seed after fertilization; the megasporangium of a seed plant with its enclosing integuments.