Biology·Organisation & maintenance · NSSCO 3.12
Co-ordination in plants (tropisms)
Narrated lesson · press play
How plants sense and respond by growing — the hormone auxin, why shoots bend towards light and roots grow down, and how we use synthetic plant hormones as weedkillers.
What you'll learn in this lesson
By the end you should be able to (NSSCO Biology 3.12):
- Define plant growth substances; describe the chemical control of growth by auxins
- Define and distinguish phototropism and gravitropism
- Explain phototropism and gravitropism in terms of auxins regulating differential growth
- Describe the use of synthetic plant growth substances as weed killers
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Miss Rachel and Mike talk through the whole topic — with the figure and working drawn live.