Strep throat is a contagious disease caused by infection with streptococcal bacteria, which causes inflammation and swelling of the mucous membranes lining the back of the throat and the tonsils.trep throat is a contagious disease caused by infection with streptococcal bacteria, which causes inflammation and swelling of the mucous membranes lining the back of the throat and the tonsils.
Once an egg cell is fertilized by a sperm, it will divide and become an embryo. In the embryo, there are stem cells that are capable of becoming all of the various cell types of the human body. For research, scientists get embryos in two ways. Many couples conceive by the process of in vitro fertilization. In this process, a couple's sperm and eggs are fertilized in a culture dish.
Embryonic stem cells, as their name suggests, are derived from embryos. Most embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro âin an in vitro fertilization clinicâand then donated for research purposes with informed consent of the donors.