Читать книгу Cell Biology - Stephen R. Bolsover - Страница 71

Plasmids are small circular minichromosomes found in bacteria and some eukaryotes. They are several thousand base pairs long and are probably tightly coiled and supercoiled inside the cell. Plasmids often code for proteins that confer a selective advantage to a bacterium, such as resistance to a particular antibiotic. In Chapter 8 we describe how plasmids are used by scientists to artificially introduce foreign DNA molecules into bacterial cells.