Leaf Structure Flashcards
Wax Cuticle
Protective layer on top of the leaf, prevents water from evaporating
Upper Epidermis
Thin and transparent to allow light to enter palisade mesophyll layer underneath it
Palisade Mesophyll
Column shaped cells tightly packed with chloroplasts to absorb more light, maximising photosynthesis
Spongy Mesophyll
Contains internal air spaces that increases the surface area to volume ratio for diffusion of gases (mainly carbon dioxide)
Lower Epidermis
Contains guard cells and stomata
Guard Cell
Absorbs and loses water to open and close the stomata to allow carbon dioxide to diffuse in and oxygen to diffuse out
Stomata
Where gas exchange takes place, opens during the day, closes during the night. Evaporation of water also takes place from here. In most plants, found in much greater concentration on the underside of the leaf to reduce water loss
Vascular Bundle
Contains xylem and phloem to transport substances to and from the leaf
Xylem
Transports water into the leaf for mesophyll cells to use in photosynthesis and for transpiration from stomata
Phloem
Transports sucrose and amino acids around the plant
Adaptations of the leaf: Large surface area
For the diffusion of carbon dioxide and absorption of light for photosynthesis
Adaptations of the leaf: Thin
Allows carbon dioxide to diffuse to palisade mesophyll cells quickly
Adaptations of the leaf: Chlorophyll
Absorbs light energy so that photosynthesis can take place
Adaptations of the leaf: Network of veins
Allows the transport of water to the cells of the leaf and carbohydrates from the leaf for respiration
Adaptations of the leaf: Stomata
Allows carbon dioxide to diffuse into the leaf and oxygen to diffuse out
