What may be the most likely reason for the existence of polar bodies? A) They act as a back-up in case the secondary oocyte becomes non-viable. B) They may be fertilized and produce a viable twin. C) They provide a structure for half of the chromosomes after cellular division. D) They add a hormonal stimulus necessary to trigger ovulation. E) They are important additional sources of estrogen.

Why is the fate of many cells determined during gastrulation? Are there many cytoplasmic determinants during this stage?

The process which prevents a zygote from forming is known by what term?

In January 2009, Natalie Suleman successfully gave birth to octuplets and became known as Octomom. She already had 6 children, and all 14 of her children were conceived via in vitro fertilization (IVF). IVF involves removing eggs from the ovary, fertilizing them with sperm in a petri dish, and transferring the resulting embryos back into a uterus to develop. It is common for two or three embryos to be transferred into the uterus of a woman undergoing IVF to increase the chances of at least one of them surviving. When Ms. Suleman became pregnant with her octuplets, Dr. Kamrava had transferred 12 embryos. His license was revoked in 2011.Multiple eggs are required for IVF to produce functional embryos because some eggs are not fertilized or do not develop normally after fertilization. Which of the following hormones would be used to stimulate the ovaries to produce multiple eggs? Select one: a. Testosterone b. FSH c. Progesterone d. Estrogen