Final answer:
Prokaryotes, such as bacteria, generally have a cell wall which is not present in all eukaryotic cells. Both cell types possess a cell membrane, ribosomes, and genetic material, but the defining feature lacking in eukaryotes and present in prokaryotes is the cell wall.
Step-by-step explanation:
The student asked what prokaryotes have that eukaryotes do not have, among the options given. The correct answer to this question is Cell wall.
Prokaryotic cells, such as bacteria and cyanobacteria, differ from eukaryotic cells in several ways. One of the most notable differences is that prokaryotic cells lack a defined nucleus and other membrane-bound organelles, with their genetic material instead located in a region called the nucleoid.
While both prokaryotic and eukaryotic cells have a cell membrane to protect the cell, a cell wall is typically found in prokaryotic cells, which provides an additional layer of protection and structural support.
Similarly, ribosomes are present in both prokaryotic and eukaryotic cells and are responsible for protein synthesis. Thus, the presence of a cell wall is something that is characteristic of prokaryotes and not a feature of all eukaryotic cells.