Essential Genetics 6th Edition by Daniel Hartl

Exercise 6

The concept that a strand of DNA serves as a template for transcription of an RNA, which is translated into a polypeptide, is known as the "central dogma" of gene expression. All three types of molecules have a polarity. In the DNA template and the RNA transcript, the polarity is determined by the free 3' or 5' group at opposite ends of the polynucleotide chains; in a polypeptide chain, the polarity is determined by the free amino group (N terminal) or carboxyl group (C terminal) at opposite ends. Each of the following statements describes one possible polarity of the DNA template, the RNA transcript, and the polypeptide chain, respectively, in temporal order of use as a template or in synthesis. Which statement is correct?