What term describes a virus that infects bacteria?

A bacteriophage specifically refers to a virus that targets and infects bacteria. This unique relationship plays a crucial role in microbiology and biotechnology. Bacteriophages attach to the bacterial cell surface, inject their genetic material, and can either lead to the destruction of the bacterial cell (lytic cycle) or integrate into the bacterial DNA (lysogenic cycle). This specificity for bacterial cells differentiates them from other types of viruses, making them a key component in understanding bacterial infections and developing treatments.

Other terms listed represent different entities: viroids are small, circular RNA molecules that infect plants; retroviruses are a type of virus that reverse-transcribes their RNA into DNA, often infecting animal cells; and prions are misfolded proteins that cause neurodegenerative diseases. Each of these has distinct characteristics and is not involved in infecting bacterial cells.