Which process involves the transfer of genetic material through direct contact between bacteria?

The process that involves the transfer of genetic material through direct contact between bacteria is conjugation. During conjugation, one bacterium transfers genetic material to another through a specialized structure called a pilus. This physical contact allows for the transfer of plasmids or other DNA, which can enhance the recipient bacterium's genetic diversity and capabilities, such as antibiotic resistance or metabolic functions.

Transformation, on the other hand, is the uptake of free-floating DNA from the environment by a bacterium. This does not involve direct contact but rather a passive process where DNA is incorporated into the recipient's genome. Transduction is the process wherein bacteriophages (viruses that infect bacteria) carry DNA from one bacterium to another, which also does not require direct contact. Replication refers to the process of copying DNA to produce new DNA molecules and does not involve the transfer of genetic material between different cells.