For population 25 years and over in Revere: 1  High school or higher: 82.2%. 2  Bachelor's degree or higher: 19.5%. 3  Graduate or professional degree: 6.2%. 4  Unemployed: 5.7%. 5  Mean travel time to work (commute): 33.2 minutes.
Plasmids are extra chromosomal, double stranded, circular DNA molecules present in bacteria. Different kinds of bacterial plasmids based on encoded genes (their roles). F-plasmids (fertility factor or sex factors): Bacterial cells with F plasmids are called F+ cells and acts as donor cells or +strain during bacterial conjugation.
pBR322 was one of the first plasmids used for the purpose of cloning. It contains genes for the resistance to tetracycline and ampicillin. Insertion of the DNA at specific restriction sites can inactivate the gene for tetracycline (an effect known as an insertional inactivation) or ampicillin resistance.owever, plasmids are not limited to bacteria; they are also present in some eukaryotes (e.g., circular, nuclear plasmids in Dictyostelium purpureum). A plasmid is a circular, double stranded DNA that is usually found in bacteria (however it does occur in both eukarya and prokarya).