adaptation in plants

AQA Science © Nelson Thornes Ltd 2006 1

B1b 5.2 Adaptation in plants

Lesson objectiveTo describe how plants are adapted

to live in their particular habitat.

Adaptations in plants



Plants take in water through their roots in the soil…

Transpiration



Transpiration

…it moves up through the plant…



Transpiration

…..and is lost through the leaves in the transpiration stream.

Corel 178(NT)



Transpiration



Stomata

There are small openings called stomata in the leaves of a plant.



These open to allow gases in and out for photosynthesis and respiration. But at the same time water is lost by evaporation.

Stomata



Rate of transpiration

When it is hot and dry, photosynthesis andrespiration take place quickly. As a result,

plants also very quickly lose water.



The potometer

A potometer can be used to measure the rate of transpiration.



Rate of transpiration

As the leaf loses water, so the air bubble moves. The distance moved over a time period is measured.



Transpiration rate

Graph of bubble movement against time.



Transpiration rate

The steeper the graph, the faster the transpiration rate!



Which potometer experiment was run in drier air?

Transpiration rate



The drier the air, the faster the transpiration rate!

Transpiration rate



Adaptations for plants growing in a dry environment

• Curled leaves.

• Moist air trapped inside the curl.

• Thick waxy cuticle.

• Stomata on the curled side only.



Adaptations for plants growing in a dry environment

Marram grass leaves will even uncurl slightly in the wet and curl up more in the dry.

Corel 46(NT)

adaptation in plants

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