Stem cells are taken from all except -

Ans. is 'a' i.e., Livero There are three accessible sources of adult stem cells in humans :Bone marrow, which requires extraction by harvesting, that is, drilling into bone (typically the femur or iliac crest),Adipose tissue, which requires extraction by liposuction, andBlood, which requires extraction through pheresis, wherein blood is drawn from the donor (similar to a blood donation), passed through a machine that extracts the stem cells and returns other poions of the blood to the donor.Stem cells can also be taken from umbilical cord blood just after bih