Answer:
The spongy mesophyll cells are adapted for gas exchange. They are loosely-packed with large intercellular air spaces where gases can readily diffuse. They have fewer chloroplasts than palisade cells, so carry out less photosynthesis . When the plant is photosynthesising during the day, these features allow carbon dioxide to diffuse into the spongy mesophyll cells, and oxygen to diffuse out of them.
