An element is a pure substance that is made from a single type of atom. Elements are the building blocks for all the rest of the matter in the world. Examples of elements include iron, oxygen, hydrogen, gold, and helium.
Since the initial discovery that the adult brain contains stem cells that generate new neurons, an important question in neurobiology has been whether or not this adult neurogenesis is functionally important.
In most cases, yes. The hollow blastocystâwhich is where embryonic stem cells come fromâcontains a cluster of 20-30 cells called the inner cell mass. These are the cells that become embryonic stem cells in a lab dish. The process of extracting these cells destroys the embryo. Donât forget that the embryos were donated from IVF clinics.