Which of the following cells would not have a well-defined nucleus but would have a thick cell wall and ribosomes?
a: onion cell
b: coli bacteria
c: human brain cell

"Coli bacteria" is the one among the following cells that would not have a well-defined nucleus but would have a thick cell wall and ribosomes. The correct option among all the options that are given in the question is the second option or option "B". I hope the answer helps you.

The organisms with no definite nucleus but with thick cell wall and ribosomes are usually bacterial cells. The onion cell is not a bacterial cell as well as the huma brain cell. E. coli is a common bacteria that causes food poisoning and is found in the intestines of animals. Answer here is B. Coli bacteria.