Magnification determination requires image scale

Steps:

• Examine the photomicrograph for scale bar or known cell dimensions in mesophyll tissue.
• Measure the length of a standard feature, like a chloroplast or cell wall, in the image.
• Compare to actual size from biology references (e.g., palisade cells ~50-100 μm).
• Calculate magnification using formula: Magnification = Image size / Actual size.

Why B is correct:

• ×280 aligns with typical low-power magnification for clear visualization of dicot mesophyll cells without excessive detail loss.

Why the others are wrong:

• A. ×280 duplicates B, but question specifies B as correct.
• C. ×3570 is too high for tissue overview, better for ultrastructure like organelles.
• D. ×7000 exceeds standard light microscopy limits for leaf tissue, suited for electron microscopy.

Not enough information: No photomicrograph provided to verify scale.

Final answer: B