AP BIOLOGY

Detailed explanation-1: -The spongy mesophyll cells contain chloroplasts but fewer than present in the palisade parenchyma. As the chloroplasts are more abundant in the compact palisade mesophyll cells than the loosely arranged mesophyll cells, the upper surface of the leaf appears deeper green as compared to the lower surface.

Detailed explanation-2: -The cells in the spongy mesophyll layer are not as closely packed as the cells in the palisade mesophyll layer. This creates air spaces inside the leaf to enable gases to move in and out. There are not as many chloroplasts in the spongy mesophyll cells as there are in the palisade mesophyll cells .

Detailed explanation-3: -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.

Detailed explanation-4: -Palisade cells contain the largest number of chloroplasts per cell, which makes them the primary site of photosynthesis in the leaves of those plants that contain them, maximizing the production of energy, converting the energy in light to the chemical energy of carbohydrates.