Here's why:

* Hereditary material covered by protein: Viruses contain genetic material (either DNA or RNA) encased in a protein coat called a capsid.

* Infects and reproduces only inside a living cell: Viruses are obligate intracellular parasites. This means they lack the machinery to replicate on their own and must hijack a host cell's resources to reproduce.

Let me know if you have any other questions!