After fertilization a developing embryos goes through several changes. At about 2-3 days, what is the embryo referred to as?

What is the purpose of the placenta? Which part of the blastocyst eventually becomes the fetal placenta? In birds, developing chicks rely on the yolk sac to provide essential nutrients, but in humans, this is not the case. Why don’t we need it to provide nutrition? What is amniocentesis? How is it done?

Sometimes a sperm cell fertilizes a polar body rather than a secondary oocyte. An embryo does not develop, and the fertilized polar body degenerates. Why is a polar body unable to support development of an embryo?

Which layer is responsible for encasing the growing embryo?

Early Embryonic Development Match the following terms to the descriptor. NOTE: If you want to change your selection, you'll need to delete the one you already chose. After you delete it, the list of choices will pop back up and you can make a different choice. Organogenesis Hollow ball of cells Gastrulation Formation of organs Cleavage Rapid cell division Cells rearrange themselves into layers Blastula

What means to retain the ability to become any cell type—including germ-line cells and gametes—when exposed to the appropriate signals in a developing embryo?

Where (specifically) does fertilization take place in the body? When the zygote divides, is it using meiosis or mitosis?

What is your opinion of the status of an 8-celled human embryo? Why?

What happens during embryogenesis?

at what point does life begins in a pregnancy, in other words, does it begin at initial conception, when it becomes an embryo, when it becomes a fetus, or is there some other point in which life begins?