Question

Select the correct statement from the following with reference to the work by Cohen and Boyer.

• A. Cohen and Boyer were the first scientists to introduce a recombinant DNA in the year 1975.
• B. They isolated the antibiotic resistance gene by dissolving a piece of DNA from a plasmid.
• C. The antibiotic resistance gene was linked to the plamid vector using the enzyme DNA helicase.
• D. The antibiotic resistance gene was isolated from the native plasmid of Salmonella typhimurium.

Answer 1

Answer: (D)

The first recombinant DNA was constructed by Stanley Cohen and Herbert in 1972. They cut the piece of DNA from a plasmid carrying antibiotic - resistance gene in the bacterium Salmonella typhimurium and linked it to the plasmid of Escherichia coli. The antibiotic resistance gene was linked to the plamid vector using DNA ligase, while the DNA was cut into pieces using restriction enzymes.