Teachers' Domain; The Life Science; Cell Differentiation

All vertebrates start the same way as one fertilized egg cell the egg will divide and form new cells will and these divide to form more cells over and over. At first and embryos development seems chaotic it soon begins taking on exquisite order fields of cells fold and slide over each other. These cells are gathering in a long line and rolling into a tube. This is the beginning of a spinal cord cell differentiation has taken place. Other cells are becoming heart cells and are forming a primitive beating heart. Each cell is ordered by a genetic program to form organs limbs tissue. To construct a body plan. At these early stages of embryonic development it's hard to tell whether this is a chick a frog or a

human being. Here bumps on the limb develop into feathers. And as the chick out close its space and food supply it is time to hatch.