What structures are found in all cells, both prokaryotic and eukaryotic?

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

Answer: (B)

Verified step by step guidance

1. Begin by understanding the basic types of cells: prokaryotic and eukaryotic. Prokaryotic cells are simpler and do not have a nucleus or other membrane-bound organelles, while eukaryotic cells do.
2. Identify the structures that are common to all cells, regardless of whether they are prokaryotic or eukaryotic. These structures are essential for the basic functions of life.
3. Consider the cell membrane, which is a fundamental structure found in all cells. It acts as a barrier that separates the interior of the cell from the external environment and regulates the movement of substances in and out of the cell.
4. Evaluate the other options given: chloroplasts, mitochondria, and nucleus. These are organelles found only in eukaryotic cells. Chloroplasts are involved in photosynthesis, mitochondria in energy production, and the nucleus houses genetic material.
5. Conclude that the cell membrane is the correct answer, as it is the only structure listed that is present in both prokaryotic and eukaryotic cells.