[maica]

This is not a scientific answer, but I played a nurse once!

We all start from 2 cells, which have the information to become the gazillion-celled persons that we are.

Embryonic stem cells are much closer to the original 2, so are much less differentiated than even the stem cells found in your baby's umbilical cord blood (after nine whole months of specialized growth.) Those cells are much more 'controllable' in a lab setting than the original 2 or 2 week-old cells.

[103198]

Thank for the clarification - but I've got some follow-up questions if you don't mind.

When is a stem cell an embryonic stem cell and not a mature (?) stem cell like found in the cord blood? Is it based on time from conception or some other factor?

Thanks,

Ben