Which cellular structure is found in both prokaryotic and eukaryotic cells?

• A. Nucleus
• B. Ribosomes
• C. Mitochondria
• D. Golgi apparatus

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the difference between prokaryotic and eukaryotic cells. Prokaryotic cells lack membrane-bound organelles, while eukaryotic cells have membrane-bound organelles such as the nucleus, mitochondria, and Golgi apparatus.
2. Step 2: Identify which cellular structures are membrane-bound organelles. The nucleus, mitochondria, and Golgi apparatus are all membrane-bound and therefore found only in eukaryotic cells.
3. Step 3: Recognize that ribosomes are not membrane-bound organelles. Ribosomes are responsible for protein synthesis and are found in both prokaryotic and eukaryotic cells.
4. Step 4: Conclude that since ribosomes are present in both cell types, they are the cellular structure common to both prokaryotic and eukaryotic cells.
5. Step 5: Summarize that the correct answer is ribosomes because they are essential for protein production and universally present in all cells.