Plant Hormones Flashcards
What is the name of the main plant hormone?
Auxin
What does auxin do to shoots (stems)?
makes them grow
What does auxin do in roots?
Stops them growing
What does auxin do in plants?
Controls growth
What are the three things that plants grow in response to?
Gravity
Light
Water
What do we call it when a plant grows in response to gravity?
Gravitropism (or geotropism)
What do we call it when a plant grows in response to sunlight?
Phototropism
What do we call it when a plant grows in response to water?
Hydrotropism
Which part of a plant produces auxin?
The tips of roots and shoots
Why does cutting the tip of a shoot off stop it growing?
Because no auxin can be produced so the shoot stops growing
When a shoot is exposed to light, more auxin builds up on the…
shaded side of the shoot
What happens to the shaded side of a shoot when auxin builds up around it?
It grows faster
It bends the shoot towards the light
When a shoot is growing sideways more auxin gathers on…
the lower side of the shoot
What happens when auxin gathers on the lower side of a sideways root?
The lower side of the root stops growing.
The root bends down towards the ground.
What happens when auxin gathers on the lower side of a sideways shoot?
The lower side grows faster.
The shoot bends upwards.
When a root is growing sideways more auxin gathers on the…
lower side of the root
Roots grow…
towards gravity (down) towards water
Shoots grow..
against gravity (up) towards sunlight
When a root is near water auxin gathers on the..
side of the root nearest the water.
What happens when auxin gathers on the side of the root nearest water?
That part of the root stops growing
The root bends towards the water
Auxin is a plant hormone that can be used by farmers as what?
Weedkillers
Rooting powders when cloning using cuttings.
Auxin weedkiller does what?
Kills broad leaved plants
Doesn’t kill narrow leaved plants
Rooting powder (used in cloning plants via cuttings) contains what?
Auxin
