AP BIOLOGY

Detailed explanation-1: -Glycoprotein spikes are found on the capsids of all viruses. Viruses are the only known infectious agents that are obligatory intracellular parasites. Binomial nomenclature is used to name viruses. A segmented genome can result in antigenic shift.

Detailed explanation-2: -A peplomer is a glycoprotein spike which are the subunits of viral envelope. These peplomeres will only bind to certain receptors on the host cell. They are essential for both host specificity and viral infectivity. So the correct answer is ‘viral envelope’.

Detailed explanation-3: -Viral glycoproteins reside on the surface of virions and are often the sole component of the virus that interacts with the external environment.

Detailed explanation-4: -Lipid envelopes are derived from the host cell. Whereas the envelope glycoproteins are virus encoded. However, there are sugars attached to the viral glycoproteins which often reflect the host cell that harboured the virus.