4.5 TRIPLE Plant hormones Flashcards
What is positive phototropism?
When plant stems grow towards light
What is positive gravitropism?
When plant roots grow downwards, with the force of gravity
What type of plant hormone is responsible for cell elongation?
Auxin
What do we call the lengthening of specific plant cells as a result of hormones?
Cell elongation
What is Hydrotropism?
A plant’s ability to grow roots towards water
What 3 things are Gibberellins responsible for?
- Cell elongation
- Seed dormancy
- Germination
Which plant hormone ripens fruit?
Ethene
As well as ripening fruit, what other roles does ethene have?
- Control of cell division
- Helps flowers open
Auxins Experiments:
What happens when the tip is covered and light is shone to the side?
It grows upwards
On which side does auxin accumulate when light is shone from the side on a stem
The shaded side
Auxin Experiments:
What was used to create an impermeable barrier to stop hormone diffusion
Mica
Where are auxins mainly produced (2 places)
- Tips of shoots
- Roots
How do auxins travel in plants?
By diffusion
How does using auxins as selective weedkillers kill plants?
- Causes some plants to grow uncontrollably
- Causes some plants to stop growing
Gardeners can take cuttings to increase the number of plants they have.
Why do they need to use auxins in this process?
Rooting powders contain auxins, which helps the cuttings form roots.
