Respuesta :
The viruses labeled with I and II in the picture presented below have a viral envelope, an outer layer of the viral particle that contains various glycoproteins.
These structures on the envelope are key factors in virus-cell recognition and viral infection of the cell.
These structures on the envelope are key factors in virus-cell recognition and viral infection of the cell.


The correct answer is D: I and II only.
Viruses have protein capsids, which protect their genetic material. This capsid sometimes is covered by viral envelopes which have glycoproteins on their surface. Glycoproteins help in the process of binding to the host cell and infecting it. In this example, virus III has the structure of a bacteriophage and it does not seem to have glycoproteins. Bacteriophages use their tail fibers to attach to the bacterial host and inject their genetic material. On the contrary, viruses I and II have glycoproteins sticking out of their envelopes.
Viruses have protein capsids, which protect their genetic material. This capsid sometimes is covered by viral envelopes which have glycoproteins on their surface. Glycoproteins help in the process of binding to the host cell and infecting it. In this example, virus III has the structure of a bacteriophage and it does not seem to have glycoproteins. Bacteriophages use their tail fibers to attach to the bacterial host and inject their genetic material. On the contrary, viruses I and II have glycoproteins sticking out of their envelopes.