Question

what is the smallest bacterial cell and largest bacterial cell?

Answer 1

the smallest bacteria is “ Mycoplasma” and the largest bacteria is “ Thiomargarita namibiensis ".

Answer 2

Mycoplasma is the smallest cell and the smallest bacteria living on earth having a size of about 0.2 micro meter
and

Thiomargarita namibiensis  biggest bacteria ever discovered ranging in size from 0.1 – 0.3 mm ( 100 – 300 micro meter ), but sometimes also has size of 0.75 mm or 750 micrometer.