Magnification from visible cell details

Steps:

• Examine the photomicrograph for fine structures like chloroplasts or cell walls with intricate details.
• Recall actual sizes: plant cell components range from 10-100 μm, with organelles ~1-5 μm.
• Estimate image scale: detailed view implies high enlargement beyond standard low-power.
• Apply magnification formula (image size / actual size) to match observed resolution to 4000x.

Why D is correct:

• 4000x oil immersion magnification resolves sub-micron plant cell features, per light microscopy limits (Abbe diffraction ~0.2 μm resolution).

Why the others are wrong:

• A. 250x: Low power for broad tissue overviews, lacks organelle detail.
• B. 400x: Medium power for cell outlines, insufficient for fine internal structures.
• C. 1000x: High dry lens for basic organelles, but below oil immersion for maximum clarity.

Final answer: D