Question

which of the following is a key distinguishing feature of a prokaryotic cell compared to a eukaryotic cell?
the presence of ribosomes to synthesize proteins.
the presence of a plasma membrane separating the cell from its environment.
the ability to use flagella for locomotion.
the lack of a nucleus and other membrane - bound organelles.

Explanation:

Prokaryotic cells lack a nucleus and membrane - bound organelles. Both prokaryotic and eukaryotic cells have ribosomes for protein synthesis and a plasma membrane. Some eukaryotic cells (like sperm cells) can also have flagella for locomotion.

Answer:

The lack of a nucleus and other membrane - bound organelles.