Plant adaptations

In a nutshell

Leaves are adapted to carry out photosynthesis efficiently. They also have adaptations to increase the efficiency of gas exchange. Some plants grow in extreme conditions, such as dry conditions, waterlogged soil and tropical conditions, therefore they must adapt in order to survive.

Adaptations for photosynthesis

Leaves are adapted to carry out photosynthesis efficiently. These adaptations are shown below.

Biology; Plant structures and their functions; KS4 Year 10; Plant adaptations

	Adaptation	Description
1.	Transparent waxy cuticle	Also allows light to pass through to the chloroplasts.
2.	Transparent epidermis cells	Allows light to pass through to the chloroplasts.
3.	Tightly packed mesophyll cells	Palisade mesophyll cells are located at the top of the leaf and they contain lots of chloroplasts which maximises photosynthesis.
4.	Thin leaves	The leaf is thin so air surrounds most of the cells. This means gas exchange can take place over a larger surface area.
5.	Phloem	The phloem tubes transport the glucose that is made during photosynthesis away from the leaf.
6.	Xylem	The xylem tubes transport water from the roots to the leaf for photosynthesis.
7.	Stomata	These pores allow carbon dioxide to diffuse into the leaf from the air and oxygen to diffuse out of the cells.
8.	Internal air spaces	These increase the surface area for gas exchange.

Dry condition adaptations

Some plants live in dry conditions with little water so they must adapt in order to carry out photosynthesis and survive.

Example

Marram grass is a type of plant that grows on sand dunes. These are often windy and do not hold much water. They have adaptations to help them survive in these conditions.

Biology; Plant structures and their functions; KS4 Year 10; Plant adaptations

	Adaptation	Description
1.	*Waxy cuticle*	Reduces water loss from the leaves.
2.	*Stomata in pits*	Reduces water loss as they are not exposed.
3.	*Leaf hairs*	These trap water vapour around the stomata which reduces water loss.
4.	*Rolled leaf*	The rolled leaves reduce air movement around the stomata. Reducing the air movement increases the humidity which reduces diffusion of water vapour.

Tropical conditions adaptations

Plants that live in tropical conditions need to adapt to wetter and darker conditions. They may have larger leaves in order to get as much light as possible for photosynthesis. They may also have 'drip tips' which are leaves with pointed tips. These allow water to run off the leaf.

Waterlogged soil adaptations

Plants that live in waterlogged soil may struggle to respire as these conditions have reduced oxygen given the lack of air spaces in the soil. To overcome this they have spongy tissue in their roots that stores oxygen and surface roots that allow them to take up oxygen from the surface of the waterlogged soil.