What is a Virus?
Viruses are particles of nucleic acid, protein, and in some cases lipids that can reproduce only by infecting living cells.
They enter living cells and, once they are inside, use the machinery of the infected cell to produce more viruses.

Virus Structures
Viruses exist in a variety of size and shapes.
A typical virus is composed of a core of either DNA or RNA, surrounded by a protein coat, or capsid.

1. T4 Bacteriophage
1. T4 Bacteriophage
2. Tobacco Mosaic Virus
2. Tobacco Mosaic Virus
3. Influenza Virus
3. Influenza Virus

Viral Infection
Bacteriophages are viruses that infect bacteria.
Here are shown two bacteriophages known as T4 and lambda.

Lytic Infection:
In a lytic infection, a virus enters a cell, makes copies of itself, and causes the cell to burst.

Famous Viruses

H.I.V. Or The Human Immunodeficiancy Virus.
It is transfered by ANY bodily fluid it Severely weakens the immune system of the subject