Drawing the palisade cell

Draw a tall, rectangular cell: it should be noticeably taller than it is wide. Add a cell wall as the outer rigid boundary and a cell membrane just inside it. Draw a large central vacuole occupying most of the interior. Place the nucleus against one side, often pushed to the edge by the vacuole.

Add many small oval chloroplasts arranged around the edges of the cytoplasm, close to the cell wall. This positioning maximises their exposure to light entering from above.

Why the shape matters

The tall, narrow shape means palisade cells can be packed tightly together in a single layer near the upper surface of the leaf. This arrangement means more cells per unit area receive direct light. The thin cell walls allow carbon dioxide to diffuse into the cell quickly, and the proximity to the upper epidermis means light reaches the chloroplasts with minimal absorption by other layers.

Linking chloroplast number to function

Palisade cells contain more chloroplasts than any other cell in the leaf. Each chloroplast contains chlorophyll, which absorbs light energy. More chloroplasts means more chlorophyll, which means a higher rate of light absorption and therefore a higher rate of photosynthesis. In exam answers, always connect the large number of chloroplasts to the increased rate of photosynthesis.