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).
The mechanism of transcription has parallels in that of DNA replication. As with DNA replication, partial unwinding of the double helix must occur before transcription can take place, and it is the RNA polymerase enzymes that catalyze this process.he mRNA formed in transcription is transported out of the nucleus, into the cytoplasm, to the ribosome (the cell's protein synthesis factory). Here, it directs protein synthesis. Messenger RNA is not directly involved in protein synthesis â transfer RNA (tRNA) is required for this.