Commercial Uses of Plant Hormones Flashcards
Homeostasis and Response (11 cards)
What are auxins used for in controlling plant growth?
Auxins are used for:
* Killing weeds
* Growing from cuttings with rooting powder
* Growing cells in tissue culture
Auxins selectively affect broad-leaved plants while leaving grasses and cereals unaffected.
How do selective weedkillers utilize auxins?
Selective weedkillers disrupt the normal growth patterns of broad-leaved plants, killing them while leaving crops and grasses untouched.
This is particularly effective because most weeds are broad-leaved.
What is a cutting in plant propagation?
A cutting is part of a plant that has been cut off, such as the end of a branch with leaves.
Cuttings typically do not root unless treated with rooting powder containing auxins.
What role do auxins play in tissue culture?
Auxins are added to the growth medium along with nutrients to stimulate cell division, forming both roots and shoots.
This process allows for the cloning of plants from just a few cells.
What is gibberellin and its primary function?
Gibberellin is a plant growth hormone that stimulates seed germination, stem growth, and flowering.
It is essential for various growth processes in plants.
What is dormancy in seeds?
Dormancy is a period when seeds do not germinate until they have undergone specific conditions such as cold or dryness.
Gibberellin can be used to alter dormancy, enabling germination at atypical times.
How does gibberellin induce flowering in certain plants?
Gibberellin can induce flowering in plants that require specific conditions, such as longer days or lower temperatures, without changing their environment.
It can also promote larger flower growth.
What effect does gibberellin have on seedless fruit?
Gibberellin helps seedless varieties of fruit grow larger, matching the size of seeded fruits.
This is particularly useful for fruits like seedless grapes.
What is ethene and its role in fruit ripening?
Ethene is a gas produced by aging plant parts that influences growth by controlling cell division and stimulating enzymes for fruit ripening.
It plays a crucial role in the natural ripening process of fruits.
How is ethene used commercially in fruit ripening?
Ethene is used to speed up the ripening of fruits either on the plant or during transport to stores.
This allows fruits to be picked firm and less damaged.
What methods can delay the ripening of fruit in storage?
Ripening can be delayed by adding chemicals that block ethene’s effects or reduce its production, or by using chemicals that react with ethene to remove it from the air.
This extends the shelf life of fruits.
