Which process allows bacteria to become more resistant by taking up naked DNA?

Bacteria can become more resistant to antibiotics or other environmental challenges through a process called transformation, which involves the uptake of naked DNA from the surrounding environment. This DNA can come from dead bacterial cells and may carry genes that confer beneficial traits, such as antibiotic resistance. Once the naked DNA is taken up by a competent bacterial cell, it can be incorporated into the cell's chromosome through homologous recombination or maintained as a plasmid, therefore allowing the bacteria to express new traits associated with the acquired DNA.

In contrast, conjugation involves the direct transfer of genetic material between bacteria through cell-to-cell contact, typically mediated by a structure called a pilus. Transduction refers to the process by which bacteriophages (viruses that infect bacteria) transfer genetic material from one bacterium to another. Replication, on the other hand, is the process by which a bacterial cell copies its own DNA prior to cell division, and it does not involve the uptake of external genetic material. Thus, transformation is the specific process that directly enables bacteria to take up naked DNA and potentially acquire new traits.