In Ecuador. As in Chile, Ecuadorian humitas are prepared with fresh ground corn with onions, eggs and spices that vary from region to region, and also by each family's tradition. The dough is wrapped in a corn husk, but is steamed rather than baked or boiled.
Approximately four days after fertilization, the zygote has about 100 cells and is called a blastocyst. When the blastocyst reaches the uterine lining, it floats for about two days and finally implants itself in the uterine wall around six days after fertilization. This signals the beginning of pregnancy.
By the end of this section, you will be able to: 1  Discuss how fertilization occurs. 2  Explain how the embryo forms from the zygote. 3  Discuss the role of cleavage and gastrulation in animal development.