What are stem cells? Do you know the difference between an
embryonic stem cell and an adult stem cell? Dr Karl dissects the
controversial world of stem cell science. Stem cells — George W
Bush didn't seem to like them. In fact, during the eight years
he was "leader of the Free World", George Bush Jr worked very
hard to restrict federal funding for any research using
embryonic stem cells. Now in 2012, the Nobel Prize for Medicine
or Physiology has been awarded for stem cell research. So, what
are stem cells, and why are they so controversial? Let's start
with "what is a stem cell?" Stem cells have two wonderful
properties. Not only can they divide to make more identical stem
cells, they can also, make other types of cells. By the way,
stem cells made all the several hundred types of cells in your
body, such as liver, heart, lung, muscle, kidney and so on.
There are five main types of stem cells. First is the totipotent
stem cell which can make every single cell needed to construct a
complete living organism su