Cell identification by structural features

Steps:

• Examine the diagram for presence or absence of key organelles like nucleus and cell wall.
• Compare to known cell types: animal cells lack cell walls, plant cells have them.
• Note if the cell is nucleated: red blood cells lose their nucleus at maturity.
• Match the biconcave, anucleate shape to red blood cells for oxygen transport.

Why B is correct:

• Mature red blood cells lack a nucleus, allowing more space for hemoglobin, as per their role in gas exchange.

Why the others are wrong:

• A: Liver cells are nucleated animal cells with organelles for metabolism.
• C: Root hair cells are elongated plant cells with nucleus and cell wall for absorption.
• D: Xylem vessels are dead plant cells without nucleus or cytoplasm for water conduction.

Final answer: B