T4 BACTERIOPHAGE, THE VIRUS IN NORMAL MODE                             
                                                                                
In spite of the image's resemblance to a rocket or a mutant spider,             
it is in fact a virus. It is unusual in that it is made up of discrete          
parts, such as the body, head and tail fibres, which can be assembled           
to produce a whole virus. The head is a squashed icosahedron.                   
Bacteriophages land on bacteria cell walls and by contracting their             
helical bodies, push a tube into the cell. The DNA is then injected             
into the cell to replicate the viruses.