When observing a sample under a standard light microscope, which of the following can you typically see?

• A. DNA double helix in detail
• B. Individual viruses
• C. Atomic structure of molecules
• D. Bacterial cells and most eukaryotic cells

Answer: (D)

Verified step by step guidance

1. Understand the resolving power of a standard light microscope, which is typically around 200 nanometers (0.2 micrometers). This limits the smallest structures you can clearly observe.
2. Recognize that DNA double helices are about 2 nanometers in diameter, which is far below the resolution limit of a light microscope, so they cannot be seen in detail.
3. Know that individual viruses generally range from about 20 to 300 nanometers, which is near or below the resolution limit, making them difficult or impossible to see clearly with a standard light microscope.
4. Recall that atomic structures of molecules are on the scale of angstroms (0.1 nanometers), which is far beyond the capability of light microscopy and require electron microscopy or other advanced techniques.
5. Conclude that bacterial cells (typically 1-10 micrometers) and most eukaryotic cells (10-100 micrometers) are large enough to be observed clearly under a standard light microscope.