Which of the following structures are not found in all prokaryotic cells?

• A. Nucleus
• B. Ribosomes
• C. Plasma membrane
• D. Cell wall

Answer: (A)

Verified step by step guidance

1. Understand the basic structure of prokaryotic cells: Prokaryotic cells are simple, single-celled organisms that lack a nucleus and membrane-bound organelles.
2. Identify the common structures found in prokaryotic cells: These typically include ribosomes, a plasma membrane, and often a cell wall.
3. Recognize that a nucleus is a membrane-bound organelle: Prokaryotic cells do not have a nucleus; their genetic material is not enclosed within a membrane.
4. Compare the given structures with those found in prokaryotic cells: Ribosomes, plasma membrane, and cell wall are common in prokaryotes, but a nucleus is not.
5. Conclude that the structure not found in all prokaryotic cells is the nucleus, as prokaryotes lack membrane-bound organelles.