...Addgene's molecular biology reference guide, including information on molecular genetics, plasmids, sequencing...years, many significant discoveries lead to the conclusions that genes encode proteins and reside on chromosomes...essential DNA sequences for this purpose, which includes a DNA replication origin, an antibiotic-resistance...whose product confers resistance to ampicillin) is included in the plasmid. These bacteria are then grown ...in molecular biology for a variety of reasons, including that they are: Easy to work with - Plasmids are...gene expression in a wide variety of organisms, including plants, worms, mice, and even cultured human cells... a DNA fragment. Commonly used cloning vectors include Gateway entry vectors and TOPO cloning vectors....