Research scientists are trying to clone a gene. In order to accomplish this task they join two pieces of DNA. Which class of the enzymes below might accomplish this task?

A: oxidoreductase

B: ligase

C: hydrolase

D: isomerase

E: lyase

B. Ligase

Explanation:

Ligase is the class of enzyme that catalyzes the joining/linking of two large molecules. This involves the formation of a new chemical bond between the molecules.

DNA ligase is an example of a ligase. It catalyzes the linking of DNA strands through the formation of a phosphodiester bond. DNA ligase can either link two complementary fragments of DNA or repair the breakage of single stranded DNA that occurs as a result of replication of double stranded DNA.