Answer:
Organelles.
Step-by-step explanation:
Eukaryotes have well defined nucleus and they have mebrane bound cell organelle. The eukaryotes are much larger in size than the prokaryotes and prokaryotes do not have the nucleus.
The cells of the eukaryotes has large size and small surface area to vloume ration. The cells of eukaryotes are compartmentalized into small structure known as organelles that perform the specific function. For example: the cell wall of plants cell maintain their shape.
Thus, the answer is organelles.