What is spongy mesophyll's primary characteristic?

The primary characteristic of spongy mesophyll is the presence of large air spaces between the cells. These air spaces are crucial because they allow for efficient gas exchange, enabling carbon dioxide to enter the leaf and oxygen to exit during the process of photosynthesis. The spongy mesophyll cells are not densely packed, which contrasts with the palisade mesophyll cells that are tightly arranged to maximize light absorption.

Additionally, the spongy mesophyll contains chloroplasts, but it is not exclusive to these cells, as palisade cells also contain them. While spongy mesophyll does provide some structural support through its cells, its main function revolves around gas exchange rather than providing support like other structures in the plant. The unique arrangement of spongy mesophyll enables the leaf to efficiently carry out its vital processes while facilitating the exchange of gases necessary for photosynthesis and respiration.