Which of the following is found in all prokaryotic cells but only some eukaryotic cells?

• A. Cell wall
• B. Chloroplasts
• C. Mitochondria
• D. Nucleus

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the key structural differences between prokaryotic and eukaryotic cells. Prokaryotic cells are simpler and lack membrane-bound organelles, while eukaryotic cells have complex internal structures including organelles like the nucleus, mitochondria, and chloroplasts.
2. Step 2: Identify which structures are universally present in prokaryotic cells. For example, all prokaryotic cells have a cell wall, which provides shape and protection, but they do not have membrane-bound organelles such as mitochondria, chloroplasts, or a nucleus.
3. Step 3: Consider the presence of these structures in eukaryotic cells. While all eukaryotic cells have mitochondria (except some specialized cells), only plant cells and some protists have chloroplasts, and not all eukaryotic cells have a cell wall (animal cells lack it).
4. Step 4: Compare the options given: cell wall, chloroplasts, mitochondria, and nucleus. Determine which is found in all prokaryotes but only some eukaryotes. Since the cell wall is present in all prokaryotes and only in some eukaryotes (like plants and fungi), it fits the criteria.
5. Step 5: Conclude that the correct answer is the cell wall, as it is a universal feature of prokaryotic cells but only present in certain eukaryotic cells.