raised (Clarke 1). The Taq polymerase begins adding nucleotides to the primer and eventually makes a complementary copy of the template. If the template contains an A nucleotide, the enzyme adds on a T nucleotide to the primer. If the template contains a G, it adds a C to the new chain, and so on to the end of the DNA strand, completing one PCR cycle. Each piece of DNA in the vial has been duplicated at the end of the cycle. But the cycle can be repeated 30 or more times. Each newly synthesized DNA piece can act as a new template, so after 30 cycles, 1 billion copies of a single piece of DNA can be produced. Taking into account the time it takes to change the temperature of the reaction vial, 1 million copies can be ready in about three hours. PCR is valuable to researchers because it allows them to multiply unique regions of DNA so they can be detected in large genomes. Researchers in the Human Genome Project are using PCR to look for markers in cloned DNA segments and to order DNA fragments in libraries. PART B The morale and safety questions surrounding genetic engineering currently cause this new science to be cast in a false light. Anti-technologists and political extremists spread incorrect interpretation of facts coupled with statements that genetic engineering is not natural and defies the order of things. The morale question of biotechnology can be answered by studying where the evolution of man is, and where it is leading our society. The safety question can be answered by examining current safety precautions in industry, and past safety records of many bioengineering projects already in place. The evolution of man can be broken up into three basic stages. The first evolution, lasting millions of years, slowly shaped human nature from Homo erectus to Home sapiens. Natural selection provided the means for countless random mutations resulting in the appearance of such human characteristics as hands and fee...
