Non-photosynthetic cells lack chloroplasts in dicot leaf anatomy

Steps:

• Photosynthesis occurs only in cells with chloroplasts, absorbing light for the process.
• Dicot leaf cross-section includes upper epidermis, palisade mesophyll, spongy mesophyll, and lower epidermis with guard cells.
• Mesophyll layers (palisade and spongy) contain chloroplasts for maximum light capture.
• Epidermal cells protect the leaf but lack chloroplasts, preventing photosynthesis.

Why B is correct:

• B is the upper epidermal cell, which lacks chloroplasts as per standard leaf anatomy, unable to perform photosynthesis.

Why the others are wrong:

• A (palisade mesophyll): Contains densely packed chloroplasts for primary photosynthesis.
• C (spongy mesophyll): Has chloroplasts enabling gas exchange and light absorption.
• D (guard cell): Possesses chloroplasts to photosynthesise while regulating stomata.

Final answer: B