What differentiates prokaryotic cells from eukaryotic cells?

• A. Prokaryotic cells lack membrane-bound organelles
• B. Eukaryotic cells are generally smaller than prokaryotic cells
• C. Prokaryotic cells have a defined nucleus
• D. Eukaryotic cells contain only one type of organelle

Answer: (A)

Prokaryotic cells are characterized by their lack of membrane-bound organelles, which is a fundamental distinction from eukaryotic cells. In eukaryotic cells, organelles such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus are enclosed by membranes, facilitating compartmentalization of cellular functions. This separation allows for more complex processes and greater efficiency in eukaryotic cells.

In contrast, prokaryotic cells, such as bacteria and archaea, do not possess these membrane-bound structures. Instead, their genetic material is located in the nucleoid region, which is not enclosed by a membrane, and they primarily carry out all cellular processes in the cytoplasm. This lack of compartmentalization in prokaryotes is indicative of their simpler cellular organization and typically smaller size compared to many eukaryotic cells.

The other options do not accurately represent the distinctions between prokaryotic and eukaryotic cells. Eukaryotic cells can often be larger than prokaryotic cells, prokaryotic cells do not have a defined nucleus, and both types of cells can contain multiple types of organelles.