Question

how does the embryo forms different types of organs in the body with the same type of cells ?

Answer 1

The single celled zygote after its formation undergoes cleavage. Cleavage, besides producing producing large number of cells in embryo by rapid division, also segregate different substances present in cytoplasm into different cells. These substances determine how the various cells develop later. Then, during gastrulation, rearrangement of these cells occurs into three germ layers: Ectoderm, mesoderm and endoderm. Cells in these germ layers undergo differentiation and specialisation to form organs and this process is called organogenesis. By moving through this long and complex pathway, a single cell called zygote could give rise to different organs in a developing foetus.