Here's why:

* Prokaryotes are single-celled organisms that lack a nucleus and other membrane-bound organelles.

* E. coli is a bacterium that is commonly found in the intestines of humans and other animals. It is a single-celled organism with a simple structure, lacking a nucleus and other membrane-bound organelles.

Other examples of prokaryotes include:

* Salmonella

* Streptococcus

* Cyanobacteria (formerly known as blue-green algae)

* Archaea, which are a group of single-celled organisms that are distinct from bacteria.