Which of the following statements about conjugation is true? A Transferring DNA between cells in conjugation requires a virus carrier. B The donor and recipient cell must be in direct contact (touching) to transfer DNA. C Conjugation can only occur between bacteria of the same species. D Conjugation can occur with or without a conjugative plasmid.

The correct answer is B) The donor and recipient cell must be in direct contact (touching) to transfer DNA.

Here’s an explanation of each option:

• A) Transferring DNA between cells in conjugation requires a virus carrier: This is false. Conjugation does not require a virus (or bacteriophage). It is a direct DNA transfer process between bacterial cells, often facilitated by a pilus, and does not involve viral mediation. This option describes transduction, not conjugation.
• B) The donor and recipient cell must be in direct contact (touching) to transfer DNA: This is true. In bacterial conjugation, the donor and recipient cells physically connect through a pilus, which facilitates the transfer of DNA, typically plasmid DNA, from the donor to the recipient cell.
• C) Conjugation can only occur between bacteria of the same species: This is false. Conjugation can occur between bacteria of different species, as long as they have the necessary machinery for conjugation (e.g., a conjugative plasmid or compatible mating systems). For example, certain plasmids can enable conjugation between species.
• D) Conjugation can occur with or without a conjugative plasmid: This is false. Conjugation typically involves a conjugative plasmid that carries the necessary genes for pilus formation and DNA transfer. While some forms of conjugation can transfer chromosomal DNA, a conjugative plasmid is essential for initiating the process.