B3.2.7 - Uses Of Plant Hormones Flashcards
What plant hormone does banana give off?
Ethene gas
How are plant hormones produced and transported?
They are produced by cells in one area of the plant and then transported to a different area to produce a response
Describe the main functions of auxins.
They stimulate growth by causing cell elongation and they also help to regulate fruit development. Without auxins, fruits are often too small.
Describe the main functions of ethene.
They cause plant fruits to ripen by stimulating the conversion of starch into sugar. It is the only plant hormones that exists as a gas
Describe the main functions of gibberellins.
They promote growth, particularly stem elongation. They can also end the dormancy period of seeds and buds, which leads to shoots and flowers opening.
What are some commercial uses of plant hormones?
Speeding up or slowing down plant growth.
What do many weed killers contain?
Auxins
What are weed killers?
Selective herbicides which kill weeds that are broad-leaved plants but do not affect narrow-leaved plants.
How does the auxin weedkiller kill weeds?
It makes the weeds grow too fast, and the rapid uncontrolled growth kills the plant
What does rooting powder contain?
Auxins
What do horticulturists and gardeners use auxin for?
Producing identical plants
How are identical plants produced?
The plant shoot is cut off, dipped into rooting powder and planted.
How is ripening delayed?
Auxin is sprayed onto fruit trees
Why is ripening delayed/
So a harvest can be collected all at the same time and fruit won’t drop off trees early
How is ripening quickened?
Ethene is sprayed onto fruit trees and plants
Why is ripening quickened?
So fruit can be ready earlier in the growing season
How can you produce seedless fruit?
Apply auxins to unpollinated flowers so insects and the wind cannot pollinate the plant and produce seeds
Why is seedless fruit produced?
As some people like fruit without seeds
Why do seeds not normally germinate at the end of summer?
As they remain dormant until conditions are ideal for growth
How do commercial growers trigger seeds to germinate in the winter?
By spraying them with gibberellins or auxins in the greenhouse
