A woman receives an organ transplant from her sister who is an identical twin. What type of graft is it?: (A) Allograft, (B) Autograft, (C) Xenograft, (D) Isograft
Answer is D. An Isograft is a graft of tissue between two individuals who are genetically identical (i.e. monozygotic twins). Transplant rejection between two such individuals viually never occurs Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 183