What species of organism does the gene donor cell belong to?

Prokaryotes, which include bacteria and single-celled microorganisms called Archaea, usually pass their chromosomal DNA on to their offspring asexually. In other words, a bacterial cell reproduces by simply replicating its chromosome and dividing into two daughter cells. The daughter cells that result from this division are genetically identical to each other and to the original parent cell. Thus, over time, asexual reproduction in bacteria can lead to a population of hundreds of thousands of cells, all of which are genetically identical to a lone original parent cell.

Given their asexual method of reproduction, it is tempting to think that bacteria are sorely lacking in genetic variation, but this is not the case. Prokaryotic cells have developed a number of methods for recombining their genetic material, which, in turn, contributes to their genetic diversity. The three most common ways that bacteria diversify their DNA are transformation, conjugation, and transduction. However, not all types of bacterial cells are capable of engaging in all three processes.