Biol 321
Name _________________________
Spring 2019
Week 5
Introduction to Stem Cells
1
Stem cells have the remarkable potential to develop into many different cell types in the body during
early life and growth. In addition, in many tissues they serve as a sort of internal repair system,
dividing essentially without limit to replenish other cells as long as the person or animal is still alive.
When a stem cell divides, each new cell has the potential either to remain a stem cell or become
another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a
brain cell.
Stem cells are distinguished from other cell types by two important characteristics. First, they are
unspecialized cells capable of renewing themselves through cell division, sometimes after long
periods of inactivity. Second, under certain physiologic or experimental conditions, they can be
induced to become tissue- or organ-specific cells with special functions. In some organs, such as the
gut and bone marrow, stem cells regularly divide to repair and replace worn out or damaged tissues.
In other organs, however, such as the pancreas and the heart, stem cells only divide under special
conditions.
Until recently, scientists primarily worked with two kinds of stem cells from animals and humans:
embryonic stem cells and non-embryonic "somatic" or "adult" stem cells. Scientists discovered ways
to derive embryonic stem cells from early mouse embryos more than 30 years ago, in 1981. The
You've reached the end of your free preview.
Want to read all 5 pages?
- Spring '19
- RNA, different cell types, stem cell divides
