During bacterial conjugation, DNA can be transferred from the donor cell to the recipient cell because a/an __________blank connects the two cells.

The correct answer to fill in the blank is "pilus."

Bacterial conjugation is a process through which genetic material is exchanged between bacterial cells. The connection that facilitates this transfer is known as a pilus, specifically a sex pilus. This structure is a thin, hair-like appendage that extends from the surface of the donor bacterium and establishes contact with the recipient bacterium. Once a stable connection is formed, the donor cell can transfer plasmid DNA or other genetic material through the pilus, leading to genetic variation in bacterial populations. This mechanism is significant in the spread of antibiotic resistance and other traits among bacteria.