There are two types of mesophyll cells:
* Palisade mesophyll cells: These are elongated cells arranged in columns just below the upper epidermis of the leaf. They contain many chloroplasts, the organelles where photosynthesis takes place.
* Spongy mesophyll cells: These are irregularly shaped cells with large air spaces between them. They also contain chloroplasts but fewer than the palisade mesophyll cells. The air spaces allow for gas exchange (CO2 and oxygen) necessary for photosynthesis.
