Define plaque, lysogeny, and prophage.

Verified step by step guidance

1. Define 'plaque' as a clear zone on a bacterial lawn where bacteriophages have infected and lysed the bacterial cells, indicating areas of cell destruction caused by viral infection.
2. Explain 'lysogeny' as a viral life cycle in which the bacteriophage integrates its genome into the host bacterial chromosome, existing in a dormant state without causing immediate lysis of the host cell.
3. Describe 'prophage' as the viral DNA that has been integrated into the bacterial genome during lysogeny, which can replicate along with the host DNA and remain latent until induced to enter the lytic cycle.
4. Clarify that plaques are visible evidence of the lytic cycle, whereas lysogeny and prophage represent a dormant phase of the virus within the host.
5. Summarize the relationship: plaques result from lytic infection, lysogeny is the dormant integration phase, and prophage is the integrated viral DNA within the host genome.

Key Concepts

Plaque

A plaque is a clear zone formed on a bacterial lawn where bacteriophages have infected and lysed bacterial cells. It represents areas of bacterial cell death caused by viral replication and release, useful for quantifying phage particles.

Lysogeny

Lysogeny is a viral life cycle in which a bacteriophage integrates its genome into the host bacterial chromosome, remaining dormant as a prophage. The host cell continues to live and reproduce, passing the viral DNA to daughter cells.

Prophage

A prophage is the viral DNA integrated into the bacterial genome during lysogeny. It remains inactive but can later be induced to enter the lytic cycle, producing new phages and lysing the host cell.