Answer to Question 1
The two basic problems associated with human organ transplant are:
1 . A shortage of organs to transplant
2 . The body's natural rejection of strange or unfamiliar tissue, leading to organ rejection
Answer to Question 2
The main advantage of producing drugs in animal urine is that the fluid is usable as soon as the genetically altered animal is born, whereas drugs from animal milk are delayed until the animal matures, reproduces, and begins to give milk.