How is an autograft different from an allograft?

An autograft is distinct because it is a type of graft that is taken from the same individual who will receive the graft. This means that the tissue used for the autograft, whether it be skin, bone, or another type of tissue, originates from the patient themselves. This characteristic reduces the risk of rejection by the immune system, as the body recognizes its own tissues as 'self' and is less likely to mount an immune response against it.

In contrast, an allograft involves tissue that is taken from a donor who is genetically different from the recipient, typically from another human. This introduces the potential for rejection because the immune system may identify the foreign tissue as a threat. The other options, such as involvement of different species, identical twins, or always being a surgical procedure, do not accurately capture the fundamental difference between autografts and allografts. Autografts specifically refer to the use of the patient's own tissue, which is key for successful integration and healing.