Answer to Question 1
The two problems with mechanical replacement valves are:
1 . Mechanical valves tend to damage the blood cells as they travel in the heart and through the valve.
2 . Mechanical valves tend to accumulate blood residue, which leads to the valve sticking, which can cause death.
Answer to Question 2
The two ways that the DNA of the organ recipient may be used to improve the chances of successful transplant include:
1 . Genetic transfer could take place and an animal with the recipient's DNA could be grown and ready within six months.
2 . The gene that controls DNA rejection could be identified and turned off.
