Plant structure
Flowering plants have a basic structure:
Leaves, stems and roots are organs consisting of different types of tissues Plant leaves are the main organ for photosynthesis.
Functions of leaves
The function of a leaf is photosynthesis. Leaves are the source of all of food on Earth.
Leaves are adapted in several ways to help them perform their function.
Features of leaves
Adaption | Purpose |
---|---|
Large surface area | To absorb more light |
Thin | Short distance for carbon dioxide to diffuse into leaf cells |
Chlorophyll | Absorbs sunlight to transfer energy into chemicals |
Network of veins | To support the leaf and transport water and sugars |
Stomata | Allow carbon dioxide to diffuse into the leaf and oxygen to diffuse out |
Inside the leaf
The internal structure of the leaf is also adapted to promote efficient photosynthesis:
Structure of leaves
Adaption | Purpose |
---|---|
Epidermis is thin and transparent | To allow more light to reach the palisade cells |
Thin cuticle made of wax | To protect the leaf from infection and prevent water loss without blocking out light |
Palisade cell layer at top of leaf | To absorb more light and increase the rate of photosynthesis |
Spongy layer | Air spaces allow carbon dioxide to diffuse through the leaf |
Palisade cells contain many chloroplasts | To absorb all the available light |