Leaves in Photosynthesis
Science: KS3, topic 1.5.3
Leaves in Photosynthesis
Leaves have some key adaptations to make sure that they photosynthesise efficiently.
The waxy cuticle
- The waxy cuticle is the waterproof top layer of the leaf.
- It prevents water from escaping from the uppermost surface.
The stoma
- The stoma are open pores which allow gas exchange with the environment.
- They can close when water is low to make sure that little is lost, meaning photosynthesis can still happen.
The spongy mesophyll
- The spongy mesophyll is a layer of cells with air spaces so that gases can diffuse in and around the leaf.
The palisade layer
- The palisade layer is a layer of tightly packed cells that are filled with chloroplasts.
- This makes sure that almost all light is absorbed and little light can pass through.
Test yourself on Leaves in Photosynthesis
The waxy cuticle stops water escaping from the top of a leaf. Why does this help the plant keep photosynthesising?
The palisade layer is packed with chloroplasts, while the spongy mesophyll has many air spaces. Why are these two layers different?