HESI A2 Biology Practice Test

Eukaryotic cells are defined by several key characteristics, one of which is the presence of mitochondria. Mitochondria are membrane-bound organelles that play a crucial role in energy production through the process of cellular respiration. This feature is significant because it illustrates the complexity of eukaryotic cells and their ability to perform specialized functions more effectively than prokaryotic cells.

In contrast, prokaryotic cells, which are generally simpler and smaller, do not contain membrane-bound organelles such as mitochondria. Instead, they have a more rudimentary structure, which includes the cell membrane, cytoplasm, and genetic material that is not organized in a nucleus. Thus, the presence of mitochondria in eukaryotic cells is not only a distinguishing factor but also a vital component of their energy metabolism.

The other answer choices do not accurately reflect the differences between eukaryotic and prokaryotic cells. Eukaryotic cells contain genetic material organized in a well-defined nucleus, while prokaryotic cells do not have a nucleus; they have their genetic material located in the nucleoid region. Furthermore, while prokaryotic cells can contain some structures akin to organelles, these are not membrane-bound