Development of Human, Chick and Frog

AP-Biology Essay The egg of the amphibian is fertilized externally and contains a large amount of yolk. After the egg is fertilized there is a reorganization of the cytoplasm. When the sperm penetrates the egg the pigment cap rotates toward the point of sperm penetration and a gray crescent appears on the side of the egg opposite the point of the sperm entry. Since the yolk is present in larger amounts the egg divides unevenly …

…end of the 12th week fine and toe prints develop. By the end of the 5th month a heartbeat can be heard with a stethoscope. The intestines contain meconium by the end of the 6th month and during the 7th and 8th month the nervous system is developed. During the last months the baby begins to acquire antibodies. During the last months the growth rate begins to slow down and the placenta regresses. ------------------------------------------------------------------------ **Bibliography**