A Levels Biology (9700)•9700/13/M/J/19

Explanation
Interpreting Shapes in Material Cross-Sections
Steps:
- View the photomicrograph as a 2D slice of the material's internal structure.
- Identify visible outlines: circular rings indicate transverse cuts of cylindrical elements.
- Rule out 3D inferences: "hollow tube" suggests longitudinal extent not shown in cross-section.
- Eliminate mismatched shapes: spheres appear circular but context points to tubular plant tissues like xylem.
Why C is correct:
- Cross-sections of tubular structures (e.g., xylem vessels) reveal circular profiles per microscopic anatomy definitions, confirming only observation 1.
Why the others are wrong:
- A includes 2 and 3, but 2 implies unseen 3D hollowness and 3 mismatches tubular context.
- B includes 2, which overinterprets the 2D view as a full tube.
- D selects only 3, ignoring evident circular outlines of cylinders, not spheres.
Final answer: C
Topic: The microscope in cell studies
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