Why do palisade layers have more chloroplasts?

Answer 1

Mesophyll tissue forms the bulk of the green leaf. It makes up the green tissue of the leaf and consists of thin-walled cells containing chloroplasts (bits that contain the chlorphyll). In most dicot plants, the mesophyll is differentiated into palisade parenchyma and spongy parenchyma. The palisade parenchyma consists of thin-walled cells which are usually cylindrical. These cells contain large numbers of chloroplasts - the organelle used for capturing light and subsequesnt photosysnthesis.

The spongy prenchyma, however, contains much lesser chloroplasts, so its main function iot photosynthesis. The spongy parenchyma has an open and net-like structure with large inter-cellular spaces that facilitate gas diffusion. The major function of the spongy parenchyma is the transport of oxygen, carbon-dioxyde and water vapour. It also is involved in the transport of water and the products of photosynthesis, the sugars. The spongy parenchyma is in close connection with the vascular bundles and the palisade parenchyma. When no clear differentiation exists between palisade and spongy parenchyma, the tissue is called mesophyll.

Answer 2

Chloroplasts belong to the cell organelle group of plastids. They occur in plant cells or in certain microorganisms. They can develop in several ways to fit different purposes.

Chloroplasts are plastids that have specialized to become the site where photosynthesis takes place. So they need to be close to the surface and exposed to the sun light (or any artificial source of light). The palisade layer sits directly under the epidermis.

Answer 3

Photosynthesis takes place there, and chloroplasts are needed for photosynthesis.

Answer 4

It is in this part of the leaf where they can get the most sunlight, and therefore collect the largest amount of chlorophyll possible (which they need for photosynthesis).