3.1 Bacteria Size,Shape,and Arrangement of Bacterial Cells Most bacteria fall within a range Cm=10-2meter from 0.2 to 2.0 um in diameter mm =10-3meter μm=10-6 meter and from 2 to Sum in length. nm=10-9meter They have a few basic shapes-spherical coccus (plural,cocci,meaning berries),rod-shaped bacillus (plural,bacilli,meaning little staffs),and spiral.Size, Shape, and Arrangement of Bacterial Cells They have a few basic shapes-spherical coccus (plural, cocci, meaning berries), rod-shaped bacillus (plural, bacilli, meaning little staffs), and spiral. Cm = 10-2 meter mm = 10-3 meter μm = 10-6 meter nm = 10-9 meter 3.1 Bacteria Most bacteria fall within a range from 0.2 to 2.0 μm in diameter and from 2 to 8μm in length