Beginning of Essay
Genetic scientists have been busy creating all kinds of solutions to some of the problems that the human and agricultural populations have been experiencing. One of the most promising has been in the area of transplantation. That is how Dolly the sheep, came about ....

Middle of Essay
.... attach to the endothelium of the blood vessels in the organ. The complement system creates gaps in vessels, allowing gaps to form and clots to accumulate. Therefore, a complement inhibitor was developed as the gene was cloned, introduced into pigs whose cells produced this protein. Another thing discovered, was that the cells lining the pig vessels have a sugar molecules called alpha-galactose, and humans have lots of antibodies against alpha-gal. Some are thinking of knocking out the gene for alpha-gal and replacing it with the human gene for type O blood sugar. One other stumbling block may be the transferense of unknown virus's like the HIV virus, ....