Missing structures in dicot leaf cross-section

Steps:

• Recall standard dicot leaf structures: upper/lower epidermis, cuticle, palisade/spongy mesophyll, guard cells (stomata), vascular bundle (xylem/phloem).
• Identify typically visible features in diagrams: epidermis layers, mesophyll cells, often cuticle.
• Note absences: guard cells regulate gas exchange on lower epidermis; vascular bundle provides support/transport in veins.
• Match choices: diagram likely shows epidermis, mesophyll, cuticle but omits guard cells and vascular bundle.

Why C is correct:

• Dicot leaves always include guard cells for stomatal control and vascular bundles for nutrient transport, per plant anatomy definitions.

Why the others are wrong:

• A: Cuticle covers epidermis; both are surface features usually diagrammed.
• B: Epidermis forms protective layers; guard cells are specialized but epidermis is core.
• D: Vascular bundle is internal; cuticle is external and standard in sections.

Final answer: C