Plant Hormones Flashcards
What is the plant growth hormone
Auxin
Where does auxin control growth in plants
At the tips of shoots or roots
What does auxin control the growth of a plant in response to
In response to light and gravity
Phototropism and gravitropism
Where is auxin produced
In the tips as it moved backwards to stimulate the cell elongation process which occur in the cells just behind the tips
What happens with extra auxin
It promotes growth in the shoots but inhibits growth in the roots which is the desired result
Why do shoots grow towards light
Because if a shoot is exposed to light more auxin will build up in the shaded side of the top which elongates this side of the tip quicker than the other side and bends it towards the light
Why do shoots grow away from gravity
The gravity produces an unequal amount of auxin in the lower side of the tip so here the tip will grow more and elongate making the tip grow upwards
Why do roots grow towards gravity
The gravity will also make an uneven amount of auxin on the lower side but because extra auxin inhibits growth the cells on the top of the root will grow faster and the root will bend downwards
What variables need to be contorllled when investigating plant growth responses
Number of seeds Type of seed Temperature Water Light intensity
What are different uses of auxins
Killing weeds
Growing from cuttings with rooting powder
Growing cells in tissue culture
Why do auxins help cuttings grow with rooting powder
Rooting powder contains auxins and therefor when a cutting is replaced in soil the auxins enable the growing to happen quickly
What is gibberellin
A plant growth hormone
What does gibberellin stimulate
Seed germination
Stem growth
Flowering
What is dormancy
The process plants will go through before germinating which is going through certain conditions
What does gibberelin uses include
Controlling dormancy so they germinate at times do the year they normally wouldn’t
Inducing flowering - to flower without any change needed in the environment
Growing larger fruit
