Photosynthesis

Question 1

List all of the adaptations of a leaf.

Answer 1

1. A large surface area that collects as much sunlight as possible
2. An arrangement of leaves on the plant that minimises overlapping and so avoids the shadowing of one leaf by another
3. Thin, as most light is absorbed in the first few millimetres of the leaf and the diffusion distance is thus kept short
4. A transparent cuticle and epidermis that let light through to the photosynthetic mesophyll cells beneath
5. Long, narrow upper mesophyll cells are packed with chloroplasts that collect sunlight
6. Numerous stomata for gas exchange
7. Stomata that open and close in response to changes in light intensity
8. Many air spaces in the mesophyll layer to allow diffusion of carbon dioxide and oxygen
9. A network of xylem that brings water to the leaf cells, and the phloem that carries away the sugars produced in photosynthesis