Leaf Adaptations
Biology: Edexcel IGCSE, topic 2.3.9
Adaptations of Leaves
The leaves of dicotyledonous plants are well adapted for photosynthesis:
Water loss
- The waxy cuticle covering the upper and lower epidermis creates a water proof barrier over the surface of the leaf, reducing water loss.
- The guard cells around stomata in the lower epidermis of the leaf close in certain conditions to reduce water loss.
Gas exchange
- Carbon dioxide and oxygen can diffuse into and out of the leaf through stomata on the lower surface of the leaf.
- There are air spaces between the spongy mesophyll cells of the leaf so carbon dioxide and oxygen can diffuse through the leaf.
Sunlight
- The palisade mesophyll cells are located just under the upper epidermis, and packed tightly together so they can absorb as much sunlight as possible.
- Palisade mesophyll cells also contain many chloroplasts for photosynthesis.