Where do both embryonic & adult stem cells...

[onewayjohn316]

...originate, & What is the difference between the two? Also, Why can't both be used in all types of cloning???

[Lpod]

embryonic stem cells come from embryos just a few days old, when the cells aren't specialized yet.

adult stem cells usually come from the bone marrow, where different blood cells are made.

its hard to convince a cell to start reproducing exponentially, so there are many complicated steps necessary for cloning. They vary with each type of cell, though I can't tell you exactly why (idk)

[janewaydeltaQ]

I agree w/Lpod, but I'd like to add that embryonic cells work best for cloning as they are the precursor cells for ANYTHING. Whereas adult stem cells are already primed to be something specific such as blood cells (red blood cells, white blood cells or platelets). Same thing for stem cells for skin, hair, etc - they are already primed to be those specific types of cells. You can't interchange a bone marrow stem cell with a hair stem cell. This why new and innovative techniques in the treatment of blood cancers is on the horizon using the patient's own adult stem cells for treatment. Hope this helps.