A double blind study is the most rigorous clinical research design because, in addition to the randomization of subjects, which reduces the risk of bias, it can eliminate or minimize the placebo effect which is a further challenge to the validity of a study.
Transcription by RNA polymerase. An RNA strand is synthesized in the 5â²âââ3â² direction from a locally single stranded region of DNA. (After E. J. Gardner, M. J. Simmons, and D. P. Snustad, Principles of Genetics, (more...).igure 10-6. Transcription of two genes. (a) RNA polymerase moves from the 3â² end of the template strand, creating an RNA strand that grows in a 5â²âââ3â² direction (because it must be antiparallel to the template strand).
Transcription is the process by which DNA is copied (transcribed) to mRNA, which carries the information needed for protein synthesis. Transcription takes place in two broad steps. First, pre-messenger RNA is formed, with the involvement of RNA polymerase enzymes.The process relies on Watson-Crick base pairing, and the resultant single strand of RNA is the reverse-complement of the original DNA sequence.he pre-messenger RNA thus formed contains introns which are not required for protein synthesis. The pre-messenger RNA is chopped up to remove the introns and create messenger RNA (mRNA) in a process called RNA splicing (Figure 5).