Spandana Vakapalli
Embryogenesis is the development by which the embryo forms and matures. In mammals, it states to early stages of prenatal development, while the foetus and foetal development are late stages. Embryogenesis is the reproduction of the egg cell with sperm cell. The first eight weeks of growth after fertilization, is an extremely complex process. After eight weeks the single cell is transformed to an organism with level of Body-plan. The excretory, circulatory, and neurologic systems all originate to develop during this stage. In the first step- by the fusion of egg and a sperm cell a zygote is formed and in the second step- the first 12-to 24-hours after a zygote is made are spent in cleavage – very rapid cell division. Zygote primarily dividing to form a lot of new cells, so it’s first few days is spent in fast mitotic division. Here, the cell number increasing at an exponential rate, this division is taking place so rapidly that the cells don’t have time to develop, so the 32 cell stage known as the morula is the similar size as the zygote.