2.21 The Leaf's structure and adaptions Flashcards
What is the wax cuticle?
It is a protective layer on top of the leaf that prevents water from evaporating
What is the Upper epidermis?
A thin and transparent layer to allow light to enter the palisade mesophyll layer underneath it
What is the Palisade mesophyll?
Column shaped cells packed with chloroplasts to absorb more light, maximising the amount of photosynthesis
What is the Spongy Mesophyll?
It contains internal air spaces that increase the surface area for the diffusion of gasses
What is the Lower epidermis?
Contains the guard cells and stomata
What is the guard cell?
Absorbs and loses water to open and close the stomata to allow carbon dioxide to diffuse in and oxygen to diffuse out
What is the Stomata?
Where gas exchange occurs, it opens during the day and closes at night. Evaporation of water also takes place here
What is the vascular bundle?
Contains the xylem and phloem to transport substances in and out of the leaf
What is the xylem?
Transports water into the leaf for the chlorophyll cells to carry out photosynthesis
What is the phloem?
Transports sucrose and amino acids throughout the plant
How does the large surface area of a leaf benefit the plant as an adaptation?
The larger the surface area the increased area of diffusion of carbon dioxide and absorbtion of sunlight
How does the thinness of the leaf benefit the plant as an adaptation?
Allows carbon dioxide to pass to the palisade mesophyll cells quickly
How does the epidermis being thin and transparent benefit the plant as an adaptation?
Allows more light to enter the palisade cells
How does the thin cuticle made of wax benefit the plant as an adaptation?
It protects the leaf without blocking sunlight
How does the spongy mesophyll benefit the plant as an adaptation?
The sponginess contains air spaces that allow carbon dioxide to diffuse through the leaf, increasing the surface area
