Question

Horizontal gene transfer can occur via

A. mitosis.

B. conjugation AND mutation.

C. conjugation.

D. mutation.

E. binary fission.

Answer 1

C. From the given list of methods Conjugation is the only mechanism that promotes Horizontal gene transfer.

Conjugation is the process by which two bacteria attach and transfer a copy of their genetic material (usually a plasmid) between one another. By this mechanism a bacterium without a specific trait can acquire it from the bacterium that has it. This promotes diversity and enables some bacteria to survive and multiply in certain harsh environments like in the presence of an antibiotic.

Mitosis and binary fission are reproductive methods by which a normal eukaryotic cell or a bacterial cell divides into daughter cells. The gene from the bacteria that divides is equally copied in both the daughter cells; however the transfer of genetic material from parents to offspring is vertical gene transfer and not horizontal.

Mutation is the only way by which a bacterium acquires a new trait in the first place, but it does not occur through gene transfer mechanisms, they are caused by any changes in the gene that occurs slowly over generations. The new traits acquired through mutations are then transferred among the population through HGT.