Spongy mesophyll is a layer of cells inside plant leaves, located beneath the palisade mesophyll and above the lower epidermis. The cells in this layer are loosely arranged with many air spaces between them. These air spaces allow gases like carbon dioxide, oxygen, and water vapour to move freely within the leaf, making gas exchange more efficient. This helps the plant carry out photosynthesis. The spongy mesophyll also helps maintain moisture inside the leaf, which supports effective gas exchange.
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