In prophase of mitosis the nuclear envelope breaks up
Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
<u>levels of organization </u>
from the smallest units of life to the largest units of the environment :
organelles >>> cells >>> tissues >>> organs >>> organ systems >>> organisms >>> populations >>> communities >>> ecosystems >>> biosphere
The answer to your question is the compact bone .