Viruses do not exhibit many features that are vital for a living being. However, they also exhibit some features that are shown exclusively by living things only. The ability to give rise to their own types is called reproduction. It is exhibited by living things only. Like living beings, viruses replicate and produce their new progeny of viral particles inside the host organisms. The ability to reproduce makes viruses similar to living beings.
Sex is important because its how we reproduce we create new life so that they can create new life and so on with out sex theres no life if that makes sense
This either attaches the virus to the host cell or dissolves the membrane letting the virus into the host cell. The viral enzymes(enzymes are again chemical compounds) multiply the viral dna copies and viral protiens. These are new viruses. These new viruses breakout of the cell to infect other cells.