Blood tests, unlike urinalysis, detect the presence illicit drugs, not inactive drug metabolites. In general, THC only remains detectable in the blood of cannabis consumers for a few hours (though low, residual levels may be detected in chronic smokers for up to 12-24+ hours if more sensitive technology is used).
Transcription & Translation: Transcription (Basic). Transcription is the process by which the information in DNA is copied into messenger RNA (mRNA) for protein production. Transcription begins with a bundle of factors assembling at the promoter sequence on the DNA (in red). Here, two transcription factors are already bound to the promoter.
The purpose of transcription is to make RNA copies of individual genes that the cell can use in the biochemistry. The purpose of translation is to synthesize proteins, which are used for millions of cellular functions.