Explain why leaves contain palisade mesophyll cells and why these cells are able to carry out photosynthesis.

OCR GCSE Biology A: Gateway Science (J247) — B1.4 Photosynthesis · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Plants are photosynthetic organisms and are the main producers of food and biomass for life on Earth. The internal structure of a leaf is adapted to maximise the rate of photosynthesis.

Model answer (4 marks)

Palisade mesophyll is a specialised plant tissue that carries out photosynthesis.
The cells are tall and tightly packed, giving a large surface area for light absorption.
They contain many chloroplasts.
Chloroplasts have chlorophyll, which absorbs light energy, and enzymes that drive the photosynthetic reactions.

Examiner tips

Use the exact terms: palisade mesophyll, chloroplasts, chlorophyll, enzymes. Show the link between cell structure and function. Keep the answer concise and to the point.

Common mistakes

Confusing palisade with spongy mesophyll. Omitting the role of chlorophyll. Using vague phrases like "light" instead of "light energy".

Mark scheme (4 marks)

Palisade mesophyll is a specialised plant tissue that carries out photosynthesis
Palisade mesophyll cells contain chloroplasts
Chloroplasts contain chlorophyll which absorbs light energy
Chloroplasts also contain the enzymes needed for photosynthesis to occur

Key terms in this question

palisade mesophyll · photosynthesis