Final answer:
Blood relatives are preferred as organ donors because they have a higher chance of compatible blood and tissue types. Immunosuppression is used in transplantation to prevent organ rejection.
Step-by-step explanation:
Blood relatives are preferred as organ donors because they are more likely to have compatible blood and tissue types, which reduces the risk of rejection after transplantation. For example, siblings have a 25% chance of being a match, while parents and children have a 50% chance. In contrast, the chance of finding a match from an unrelated donor is much lower.
Immunosuppression plays a crucial role in transplantation. It involves the use of medications to weaken the immune system and prevent it from attacking and rejecting the transplanted organ. This allows the recipient's body to accept the donor organ and increase the chances of a successful transplant.