1. Biology
Plant Responses

2. What is a tropism? water light gravity
Tropism is a when a plant changes its growth in response to a stimulus (a change in their environment)
water
light
gravity

3. How do plants respond to light?
A plant’s response to light is called phototropism.
light
Plants grow towards light,
Why do plants grow towards light?
Plants need light for photosynthesis, so they respond
to light by growing towards it.

4. How do plants always grow the right way up?
What conditions will affect how a plant grows?

5. Geotropism shoots grow up (against gravity) gravity roots grow down
A plant’s response to gravity is called a geotropism.
Different parts of a plant have different responses to gravity.
shoots grow up (against gravity)
This allows them to get light for photosynthesis
gravity
roots grow down
(with gravity)
This allows them to get water from the soil

6. Test yourself… What is a tropism Explain what the word stimulus means
Describe what phototropism is, how is works and why
Describe what geotropism is, how is works and why.

7. What do different tropisms mean?