The division of bacteria into multiple groups form different structures like the chainlike division is called streptococci; the grapelike cluster is called staphylococci. Similarly, a group of eight bacteria into the cubelike structure is called sarcinae.

Pleomorphic bacteria lack a single characteristic shape. Most of the bacteria are of monomorphic while corynebacterium is pleomorphic and has many shapes.

Mycolic acid is present in the cell wall of acid-fast bacteria which helps in retaining its color during the acid-fast test while non acid-fast bacteria decolorized after reacting with acid-alcohol.

Peptidoglycan is a specific feature of bacteria; it is present in the cell wall of bacteria and composed of NAG and NAM acid. Gram-negative bacteria have a thin peptidoglycan layer while gram-positive bacteria have a thick peptidoglycan layer.