Which statement best describes bacteriophages?

A. A: Immediate host cell lysis after infection characterizes the lytic cycle, not the lysogenic cycle. In the lytic pathway, viral DNA hijacks host machinery, replicates rapidly, and leads to destruction of the host cell. Lysogeny instead involves a dormant phase without immediate lysis.

B. B: Release of viral particles through budding from the host membrane is typical of enveloped animal viruses, not bacteriophages. Bacteriophages infect bacterial cells and do not use membrane budding as a release mechanism.

C. C: Viral RNA remaining free in the cytoplasm without replication does not describe lysogeny. In bacteriophages, the viral genome is DNA, and during lysogeny it integrates into the bacterial chromosome rather than remaining free and inactive in the cytoplasm.

D. D: In the lysogenic cycle, bacteriophage DNA integrates into the bacterial host genome and becomes a prophage. The viral DNA replicates passively along with the host chromosome during cell division without causing immediate cell death. This allows the virus to persist in a dormant state until conditions trigger entry into the lytic cycle.

E. Both A & E are correct: Immediate host cell death following attachment or infection describes the lytic cycle, not lysogeny. In lysogeny, the host cell survives and continues to replicate while carrying the integrated prophage within its genome.

The COVID-19 virus, scientifically known as SARS-CoV-2, is an RNA virus, not a DNA virus. Its genetic material consists of single-stranded positive-sense RNA, which serves as a template for viral replication and protein synthesis inside host cells. RNA viruses generally have higher mutation rates than DNA viruses due to the lack of proofreading mechanisms during replication. Understanding the RNA-based genome of SARS-CoV-2 is crucial for developing diagnostic tests, vaccines, and antiviral therapies. Classifying it correctly as an RNA virus also distinguishes it from DNA viruses, which replicate using DNA as their genetic material and follow different replication strategies.