Answer:
PLZ MARK ME AS BRAINLIST....
Explanation:
ANSWER OF 1ST QUESTION -
1) it protects the nucleic acid from digestion by enzymes, 2) contains special sites on its surface that allow the virion to attach to a host cell, and 3) provides proteins that enable the virion to penetrate the host cell membrane and, in some cases, to inject the infectious nucleic .
ANSWER OF 2ND QUESTION -
Mutations can produce viruses with a reduced pathogenicity, altered host range, or altered target cell specificity but with intact antigenicity. Such viruses can sometimes be used as vaccine strains.
