Plant Hormones Flashcards
What is a stimulus?
A change in a factor that is detected by receptors
What is a response?
An action that occurs due to a stimulus
What is a tropism?
A growth movement in response to a stimulus
What is a movement towards a stimulus called?
Positive tropism
What is a movement away from a stimulus called?
Negative tropism
What is a phototropism?
A growth movement in response to light
What type of phototropism do the following have:
- Plant shoots
- Plant roots
Plant shoots- positive phototropism for photosynthesis
Plant roots - negative phototropism
What is gravitropism?
A growth movement in response to gravity
What type of gravitropism do plant roots have?
Positive gravitropism- anchor the plant in place + recap moisture underground
What is an auxin?
A group of plant hormones, which affect the growth and elongation of cells.
Where are auxins produced in a plant?
The very tip of the shoot
How do auxins help a plant (process)?
1) They are produced at the very tip of the shoot and move down the shoot
2) As auxins move downwards, they move to the shaded areas of the shoot
3) Here, they control cell elongation, to receive as much sunlight as possible
What happens to the following shoots:
- intact shoot
- black paper covered shoot
- tip of shoot removed + replaced with transparent cap
- shoot bends towards light
- no bending
- shoot bends towards light
What happens to the following shoots:
- tip removed
- tip removed + replaced with impermeable block
- tip removed and replaced on agar block
- no bending
- no bending
- shoot bends towards the light
In the bottom of the plant, where can auxins also be found?
Root tips
