Plant Hormones

Created by

Hannah Skipworth

Cards (12)

What is a tropism ?
Response of a plant to a specific stimulus
What is phototropism ? 
Response of a plant's shoot or root to light
What is gravitropism ? 
Response of a plant's shoot or root to gravity
What is auxin ? 
A hormone
Controls the growth of a plant's shoots and roots
When auxin is unevenly distributed
The rate of growth will be unequal
How do plant shoots show positive phototropism ?
One side of the shoot is in the light
Auxin moves to the shaded side
The shaded cells are stimulated to grow
Shoot bends towards the light
So photosynthesis can occur at a faster rate
How do plants show negative gravitropism ?
In a horizontal shoot auxin accumulates on the lower side due to gravity
Cells on the lower side grow more
The shoot bends away from the direction of gravity
More light is available for photosynthesis
How do plants show positive gravitropism ?
In a horizontal root auxin accumulates on the lower side
Cause upper cells to grow less
So root bends in the direction of gravity
So more water and nutrients are available to the roots
What are gibberellins ? 
Plant hormones
Used in seed germination
What is ethene ?
Plant hormone
Involved in cell division and ripening
What are the uses of auxins ?
Weedkillers - causes cells to grow at a rapid rate causing plant death
Rooting powder - causes new plant to grow quickly
Tissue culture - promotes growth of roots and shoots
What are the uses of ethene ?
Control of food ripening in the food industry
What are the uses of gibberellins ?
Termination of seed dormancy
Promotion of flowering
Increase of fruit size