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.
The cells represented in the cleavage stage have the ability to form all the cells. necessary for normal development (stem cells). 2. Cell number may be decreased, increased, or altered without effect to the embryo. 3. The 16 cell stage is termed the Morula (app. 3 days). 4. The cells of the Morula are pluripotent!