Plant organisation
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 A group of different tissues that work together to carry out a particular function, eg heart and lungs. for A chemical process used by plants to make glucose and oxygen from carbon dioxide and water, using light energy. Oxygen is produced as a by-product of photosynthesis. Algae subsumed within plants and some bacteria are also photosynthetic..
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 |
| Adaption | Large surface area |
|---|---|
| Purpose | To absorb more light |
| Adaption | Thin |
|---|---|
| Purpose | Short distance for carbon dioxide to diffuse into leaf cells |
| Adaption | Chlorophyll |
|---|---|
| Purpose | Absorbs sunlight to transfer energy into chemicals |
| Adaption | Network of veins |
|---|---|
| Purpose | To support the leaf and transport water and sugars |
| Adaption | Stomata |
|---|---|
| Purpose | 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 |
| Adaption | Epidermis is thin and transparent |
|---|---|
| Purpose | To allow more light to reach the palisade cells |
| Adaption | Thin cuticle made of wax |
|---|---|
| Purpose | To protect the leaf from infection and prevent water loss without blocking out light |
| Adaption | Palisade cell layer at top of leaf |
|---|---|
| Purpose | To absorb more light and increase the rate of photosynthesis |
| Adaption | Spongy layer |
|---|---|
| Purpose | Air spaces allow carbon dioxide to diffuse through the leaf |
| Adaption | Palisade cells contain many chloroplasts |
|---|---|
| Purpose | To absorb all the available light |
Learn more about plant organisation with Dr Alex Lathbridge.
Listen to the full series on BBC Sounds.
In this podcast, learn the key facts about plant organisation. Listen to the full series on BBC Sounds.
