THE POLYMERASE CHAIN REACTION (PCR) OBTECTIVE: To amplify a region of ribosomal DNA from a small amount of genomic DNA. INTRODUCTION: The polymerase chain reaction (PCR) was developed in 1983 by Kary Mullis, a nucleic acids chemist (then at Cetus).HE POLYMERASE CHAIN REACTION (PCR) OBTECTIVE: To amplify a region of ribosomal DNA from a small amount of genomic DNA. INTRODUCTION: The polymerase chain reaction (PCR) was developed in 1983 by Kary Mullis, a nucleic acids chemist (then at Cetus).
The elements on the periodic table are divided in three categories which are metals, non-metals and metalloids. Metals and nonmetals are two categories that are used to classiâ¦fy  the elements in the periodic table. The third is inert gases. 7 people found this useful.
As such, none of these metals could possibly serve as a basis for life chemistry. That leaves only the main group elements for further consideration. Main group elements can be further divided into four subgroups: non-metals, metals, metalloids, and noble gases. Non-metals (green, figure 2)âincluding carbon, nitrogen, oxygen, hydrogen, sulfur, and phosphorusâare the heroes of our story because they are the principal components of all known life.