Astudent examines a cell under the microscope and determines that it is a eukaryote. all but one structure could the student come to this conclusion. which structure is of no ?

The following cell organelles are of no use as they are in common to both the cells-

a) Plasma membrane or cell membrane

b) Ribosomes,

c) Cytoplasm, and

d) DNA.

Explanation:

All those cell organelles which are common in both prokaryote and Eukaryotes will be of no use in establishing a  difference between them .

Here in this case while examining a cell, a student can be able to identify a prokaroyte or a eukaroyte cell only when the cell organelles which are found in one are absent in the other one.

Thus,  the following cell organelles are of no use as they are in common to both the cells-

a) Plasma membrane or cell membrane

b) Ribosomes,

c) Cytoplasm, and

d) DNA.