Question

On the basis of shapes, bacteria are grouped under how many categories?

Answer 1

Bacteria are classified into 5 groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes).

Answer 2

they are among smallest and oldest organisms on our planet and are found in generally four shapes 1.rod shaped(bacilli)
2.spherical (cocci)

3.curved(commas)
4.spiral (spirilla)