a virus uses leg-like appendages to clamp onto a cell and a spike or chemical coating to penetrate the cell wall http://www.wisegeek.com/what-is-the-difference-between-a-virus-and-a-bacteria.htm
Yes, the host is living, whether it be a host for a virus, a worm, or a bacterium.
bacterium
A micro-organism, such as a bacterium, a virus or a fungus, that invades a host and causes a disease is called a pathogen.
virus
reproduction engine
A virus does not need a crystal to reproduce, as they are not living organisms and do not have cellular machinery to perform reproduction. However, a virus does need a host cell to replicate and produce new virus particles.
lytic cycle
Bacteria cells. They are the smallest living thing on Earth (known to man).
a virus
A virus injects its DNA into the host cell making it produce multiple copies of that DNA and multiple copies of the protein capsule of that virus. After a while, the host cell becomes full of many copies of that virus, then the host cell explodes releasing all the new viruses. If the host cell is a bacterium and the the virus is a bacterophage, this phenomenon is done in two ways either by the lytic cycle in which virus DNA survives and the bacterial cell is destroyed,or the lysogenic cycle in which virus DNA is incorporated in the host cell DNA.
An organism that can provide a source of energy for a virus or another organism is called a host. The host organism can provide resources and nutrients necessary for the growth and reproduction of the virus or another organism that depends on it for survival.
Active virus is technically parasitic in nature and lie dormant until a host is present so they can reproduce. Active bacterium are present in the air and most are even good. Bacteria is already alive and reproducing.