What does auxin do?
Controls growth near the tips of shoots and roots
Where is auxin produced?
The tips and moves backwards to stimulate the cell elongation which occurs just behind the tips
What happens if the tip is cut?
Auxin is removed and the tip will stop growing
What is phototropism?
A response to light
What is geotropism?
The response to gravity
Where does the shoot grow?
Towards the light and away from gravity
What happens to the plant if the tips are removed?
No auxin available
Plant stops growing
Which do shoots grow ?
Away from gravity
Which way do roots grow ?
When a plant is exposed to light, where does auxin accumulate ?
More on the side that’s in the shade than in the light
Why is an advantage for a plant to grow towards the light?
Increases the amount of light so pants can photosynthesis
What variables should u control when investigating the direction of growth for a plant ?
- light intensity
- type of seed
- number of seeds
What are the commercial uses of auxin ?
- killing weeds
- as rooting powder
- promoting growth in tissue culture
What are the commercial uses of gibberellin ?
- end seed dormancy
- promote flowering
- increase fruit size
What does the hormone gibberellin do ?
Stimulates- seed germination
- stem growth - flowering
What is dormancy ?
When seeds won’t germinate if they have been left in certain conditions either the cold or left in dryness
What does ethene stimulate ?
The ripening of fruit
When is Ethene used in commercial situations?
How does auxin powders kill weeds ?
Effects there normal growth patterns
Eventually kills them
Why is growing from cuttings with rooting powder useful?
They can produce clones
Name the plant hormone responsible for both phototropism and gravitropism