Question

A limiting factor for viral infection is

A) internal metabolic temperature of the host cell.
B) nutrition of the host cell.
C) stage of cell cycle of the host cell.
D) presence of specific receptor molecules on the host cell.

Answer 1

A limiting factor for viral infection is the existence of specific receptor molecules on the host cell required for virus attachment and entry.

Step-by-step explanation:

A limiting factor for viral infection is the presence of specific receptor molecules on the host cell. Viruses are essentially obligate intracellular parasites that can only infect host cells that express the specific surface molecules, known as viral receptors, required for the virus to attach. This specificity is akin to a lock-and-key mechanism where only the correct key (virus) fits into the specific lock (receptor on the host cell). Metabolic differences in host cells also play a role in the virus's ability to replicate once inside, but it is the initial interaction with the receptor that determines whether a virus can attach and enter a cell.