Plant Hormones Flashcards
What is a plant hormone?
Auxin
What does an auxin do?
Controls the growth of a plant near the tips of shoots and roots
What does an auxin control the growth in response to?
Light (phototropism)
Gravity (gravitropism/geotropism)
Moisture
Where is auxins produced?
Tips of a plant
How does auxins stimulate the cell elongation process?
They move backwards which occurs in the cells just behind the tips
What happens if the tip is removed?
No auxins are available and the shoot may stop growing
Do shoots grow away or towards the light?
Towards
Do shoots grow away or towards gravity?
Away
Do roots grow away or towards gravity?
Towards
Do roots grow away or towards moisture?
Towards
When a tip is exposed to light where do the auxins go?
To the shaded side so the plants grows quicker on the shaded side
It bends towards the light
When a shoot is growing sideways why does it grow away from gravity?
The gravity produces an unequal distribution
More auxins on the lower side
Lower side grows faster so it bends upwards
Why does a root grow towards gravity?
More auxins on its lower side
The extra auxin inhibits growth
Meaning the cells on top elongate faster
Root bends downwards
Why does roots grow towards moisture?
More auxins go to the side with more moisture
This inhibits growth on the side with more auxins
Root bends towards moisture
