Which of the following is NOT an effect of complement activation?Group of answer choicesBacterial cell lysisInterference with viral replicationOpsonizationIncreased phagocytic activityIncreased blood vessel permeability

The option that is NOT an effect of complement activation is "Interference with viral replication".

Here's why:

1. Bacterial cell lysis: This is an effect of complement activation. The complement system can form a Membrane Attack Complex (MAC) that can puncture the cell wall of bacteria, leading to its lysis.

2. Interference with viral replication: This is NOT an effect of complement activation. The complement system primarily targets bacteria and does not have a direct role in interfering with viral replication. That's more the job of the immune system's antiviral mechanisms, such as interferons and cytotoxic T cells.

3. Opsonization: This is an effect of complement activation. Opsonization is the process by which a pathogen is marked for ingestion and destruction by a phagocyte. Complement proteins can bind to the surface of bacteria, effectively marking them for destruction.

4. Increased phagocytic activity: This is an effect of complement activation. As mentioned above, the complement system can opsonize bacteria, which increases phagocytic activity.

5. Increased blood vessel permeability: This is an effect of complement activation. Complement activation leads to the release of anaphylatoxins which can increase the permeability of blood vessels, allowing immune cells and other molecules to reach the site of infection more easily.