AP BIOLOGY

Detailed explanation-1: -In leaves, cells in the mesophyll (the tissue between the upper and lower epidermis) are uniquely suited to carry out photosynthesis on a large scale. This is due to their high concentration of chloroplasts, which are the sites of photosynthesis.

Detailed explanation-2: -The mesophyll can be further broken down into two layers, the palisade layer and the spongy layer, both of which are packed with chloroplasts, the factories of photosynthesis.

Detailed explanation-3: -However, the palisade cells usually contain more chloroplasts than the spongy cells.

Detailed explanation-4: -Leaves are complex organs consisting of many different cell types (see Figure 1) including the epidermis, palisade mesophyll layer, spongy mesophyll layer, and vascular bundles.

Detailed explanation-5: -Answer and Explanation: The palisade layer has more chloroplasts than the spongy layer. This makes sense since the palisade layer is located on the top of the leaf and thus comes into contact with more light than the spongy layer. The spongy layer is more important for gaseous exchange.