Final answer:
Viruses have specific receptors for interacting with host cells, limiting their infectiousness to a particular host or cell type. This makes the statement true.
Step-by-step explanation:
True.
A virus attaches to a specific receptor site on the host cell membrane through attachment proteins or glycoproteins. The specificity of this interaction determines which cells can be infected by a particular virus. For example, the virus that causes human influenza binds to receptors on cells of the respiratory system, limiting its infectiousness to those specific cells. Similarly, viruses that infect animals often cannot infect humans due to differences in the cell-surface receptors.