plant hormones, phototropism and geotropism Flashcards
What are uses of auxin?
- Weed killers
- Promotion growth in tissue culture
- Rooting powders
What is the use of ethene?
Control the ripening of fruit during storage and transport
What are the uses of gibberellins?
- End seed dormancy
- Promote flowering
- Increase fruit size
What type of phototropism occurs in the stem?
- Positive phototropism
- Stem grows towards light
What type of phototropism occurs in the roots?
- Negative phototropism
- Roots grows away from light
Where are auxins made?
In the tips of growing stems and roots (can diffuse to other parts of stems or roots)
How does auxin affect growth?
By promoting cell division and causing elongation in plant cells.
How do cells in the stem respond to auxin?
Grow more
How do cells in roots respond to auxin?
Grow less
What is phototropism caused by?
Uneven distribution of auxin
How does phototropism occur in the stem?
- Auxin accumulates on the shaded side and stimulates cell growth.
- The shaded side grows faster and longer
- Stem grows towards light
How does phototropism occur in the roots?
- Auxin accumulates on shaded side
- Causes cells to grow less and shaded side to grow shorts
- Roots bend away from light
What is phototropism?
A plant response to the stimulus of light
What is geotropism?
A plant response to the stimulus of gravity
What is negative geotropism?
When the stem grows against the force of gravity
