5.4 Plant hormones Flashcards
(11 cards)
Why do plants produce hormones?
To coordinate and control growth and responses to light (phototropism) and gravity (gravitropism or geotropism).
What is a tropism? (1)
The response of a plant to a specific stimulus.
What is phototropism? (1)
The response of a plant’s shoot or root to light.
What is gravitropism? (1)
The response of a plant’s shoot or root to gravity.
What is an auxin? (1)
A hormone which controls the growth of a plant’s shoots and roots.
What happens when auxin is unevenly distributed? (1)
The rate of growth will also be unequal a growing plant.
What are gibberellins?
A plant hormone which initiates seed germination.
What is ethene? (1)
A plant hormone which controls growth and ripening of fruit.
What are the uses of auxins? (3)
- Weedkillers: causes cells to grow at rapid rate, causing death.
- Rooting powder: causes new plant to grow really fast.
- Tissue culture: promotes growth of roots and shoots
What are the uses of ethene? (1)
Control ripening of fruits during storage and transport - fruits = ripe just before sold.
What are the uses of gibberellins? (3)
- End seed dormancy
- Promote flowering
- Increase fruit size
