Unit 3 :Plasmid genetics S.Y.Micro Sem 4 genetics
Unit 3 :Plasmid genetics 1. Types of Plasmid 2. Propertie of Plasmid 3. Plasmid Replication 4. Plasmid incompatibility 5. Plasmid curing 6. Plasmid amplification concepts Plasmid Definition A plasmid is a small, circular piece of DNA that is different than the chromosomal DNA. Plasmids are defined as extra-chromosomal genetic elements, occurring chiefly in bacteria and rarely in eukaryotic organisms. In bacteria, plasmids are circular double-stranded DNA molecules which contain genes controlling a wide variety of functions. In yeast (Saccharomyces cerevisiae) an RNA plasmid has been found. This simplified figure depicts a bacterium’s chromosomal DNA in red and plasmids in blue. Functions of Plasmids Plasmids have many different functions. They may contain genes that enhance the survival of an organism, either by killing other organisms or by defending the host cell by producing toxins. Some plasmids facilitate the process of replication in bacteria. Properties of P