The host range of a virus is determined by A. whether the glycoproteins or capsid proteins on its surface recognize those of the host cells. B. whether its nucleic acid is DNA or RNA. C. the proteins in the host's cytoplasm. D. the enzymes produced by the virus before it infects the cell E. the enzymes carried by the virus

A. whether the glycoproteins or capsid proteins on its surface recognize those of the host cells.

Explanation:

Virus has different surface proteins that are recognized by the receptors present on its host cell. The range of a virus is determined by the recognition of these proteins by the host cell.

The interaction between the receptor on the host cell and surface proteins on the viral capsid is important for viral genome entry in the host cell and to determine the range of the host cells.

If the surface protein of the virus is not able to bind to the receptor on any cell then the virus can not infect the cell. For example, the HIV virus infects only those cell which have CD4 receptors. So the right answer is A.

they deliver oxygen to the blood

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.