We have two lungs, two kidneys, two ears, etc., but only one liver.
Most clinical transplants are from living relatives or cadaveric donors.
A graft between genetically dissimilar members of the same species is called an allograph. Living donors are accepted only in kidney transplants and bone marrow transplants. Have students call local or national organizations to find out more about organ transplantations. Divide the class into groups by organ. Important information to include would be the number transplanted, the survival rate, and the number of people on a waiting list for a donor organ.