Question

in what respect bcteria is considered a simple organism

Answer 1

bacteria is a single celled organism
hence, it is called as simple organism

Answer 2

bacterias are very small organisms.
 They are prokaryotic microorganisms.
Bacterial cells do not have a nucleus, and most have no organelles with membranes around them..........
 Bacteria are made up of one cell, so they are a kind of unicellularorganism.