The palisade mesophyll is superior to the spongy mesophyll (in most leaves) which aids in photosynthesis, but also serves a "sun block" to the more sensitive cells the spongy mesophyll.

The region in the leaf that has air spaces to facilitate the movement of gasses is the mesophyll region. This region is composed of layers of cells.

yes :)

The palisade mesophyll is superior to the spongy mesophyll (in most leaves) which aids in photosynthesis, but also serves a "sun block" to the more sensitive cells the spongy mesophyll.

Guard cells , spongy mesophyll layer and upper epidemic