Embryo is a state of animals and plants inside womb or seed. It is an early developmental stage start after fertilization to untill fetus state. When any seed start germination the embryo stage started.
In human embryonic stage starts with implementation and remains 8 week after conception.
In plant embryo contains radicle and cotyledon. It is just like a rudimentary plant inside the seed.
After 8th week of pregnancy the developing human is called fetus. Fetus period starts after embryonic period.
After fertilization of female egg cell by male sperm cell produces zygote.
Zygotes undergoes into cell division and forms blastomere. Blastomere undergoes into forming different shape and forms morula. When cavity forms in it is called blastocoel. The structure is called blastocysts.
