What term describes when the donor and recipient individuals are genetically identical?

The term that describes when the donor and recipient individuals are genetically identical is "isogeneic." In isogeneic transplants, the donor and recipient are genetically identical, usually occurring in situations involving twins or in specially bred animals. Since they share the same genetic makeup, the risk of immune rejection is significantly lower, making isogeneic transplants ideal for many biomedical applications.

In contrast, xenogeneic refers to transplants between different species, allogeneic pertains to transplants between genetically different individuals of the same species, and autologous means that the donor and recipient are the same individual, but not necessarily genetically identical. Understanding these definitions is essential for comprehending the complexities of transplantation medicine and the implications for immunological responses.