The formation of an embryo begins with fertilization, where a sperm and egg combine to form a zygote. This zygote undergoes a series of cell divisions known as cleavage, leading to the formation of a blastocyst. The blastocyst then implants into the uterine wall, followed by the process of gastrulation, where the three germ layers (ectoderm, mesoderm, and endoderm) are established, setting the stage for organ development. Finally, through organogenesis, the basic structures of the embryo are formed.
Placenta.
meiosis...fertilization...mitosis
Fertilization, cleavage, blastulation, gastrulation, organogenesis.
embryo
During the embryonic period, the embryo undergoes processes such as cell division, differentiation, and the formation of basic body structures and organs.
The protective structure that forms around a human embryo is called the amniotic sac or amnion. This sac contains amniotic fluid, which cushions and protects the developing embryo during pregnancy.
It depends on what organism the embryo comes from.
The embryo in a seed is the precursor to a new plant and contains the genetic material needed for growth and development. It is responsible for germination, where it sprouts and forms the roots, stem, and leaves of the new plant.
embryo
Amniotic membrane or amniotic sac, containing the embryo and amniotic fluid.
This is called the zygote. As it divides, it forms the embryo.
There really isn't much difference between a zygote, embryo, and fetus. A zygote forms after fertilization and becomes an embryo, which later becomes a fetus.