why o blood group is called the universal donor ????????????

Dear Student,

@ Cedrick: Yes, Kirti is very much correct. O blood group is a universal donor because it can be donated to people with any other blood group. Basically O- blood group is a universal donor as O+ blood group cannot be donated to people with O- blood group.

@ Kirti: Good answer!! We really appreciate your contribution to this forum. Keep posting!

Cheers!!