How about emphasizing Pre Implantation Genetic Diagnosis (PIGD)? You would have to go into the assisted reproductive technology involved, also which inherited conditions can be effectively diagnosed. It would also be a good idea to expand on one such specific condition, emphasizing the biochemistry, e.g. CF or SCA would be better than Down Syndrome because the biochemical genetics is better developed. Emphasize on the biochemistry aspect alot, this is for a biochemistry class.