Phototropism
Phototropism is the growth movement of a plant part in response to light.
Practice This ConceptMain explanation
Teacher explanation
Phototropism is seen when plant parts grow towards or away from light. Shoots usually show positive phototropism and grow towards light to get more energy for photosynthesis. Roots generally do not show strong positive phototropism. The key idea is that light acts as the stimulus and the growth direction changes because of it.
Example
A sunflower shoot bending towards sunlight is a common example of phototropism.
Simple analogy
Photo means light, so phototropism means light-guided growth.
Common confusion
Students often think roots and shoots always react the same way to light. They do not. Shoots usually grow towards light, while roots generally do not.
Exam tip
If the stimulus is light, use the term phototropism and state whether the growth is towards or away from the light.
Answer writing and exam use
1-mark use
Write the exact meaning of phototropism in one clean line.
2-mark use
Define phototropism and add one example or condition.
3-mark use
Explain phototropism, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.
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