The statements above are true;
In a host-versus-graft rejection the recipient's immune system recognizes the donor's tissue as foreign and rejects the transplant. On the other hand, in a graft-versus-host rejection, the donor tissue recognizes the recipient's tissue as foreign and the transplant rejects the recipient, causing destruction of the recipient's tissue and possibly death. Its important also to note that there are two types of rejection, the acute rejection, where the rejection of transplanted tissue that occurs several weeks after transplant. it is delayed hypersensitivity reaction, and the chronic rejection is a rejection of transplanted tissue that can occur at a late time. Immune complexes form in the arteries supplying the graft, choking off the blood supply and the tissue is rejected.
I would tell the room mate that what i just heard was the resemblance between the Fayum catarrhines and the Miocene proconsulids in skull form and dentition which suggests an evolutionary relationship, even if the direct fossils evidence is not present. Primates are divided into two groups; the prosimians and anthropoids. Monkeys evolved from Prosimians during the Oligocene Epoch while Apes evolved from the Catarrhines in Africa during the Miocene Epoch. Apes are then divided into the lesser apes and the greater apes.
Geological process is the change in the soil as a result of dust and loose rocks are removed by any natural means.