Plant and Animal Responses Flashcards
What are the four plant hormones?
Auxin, Ethene, Gibberellin and Abscisic acid
What do auxins do?
cause cell elongation in stems, inhibits cell elongation in roots.
Also inhibits lateral bud growth, preventing leaves from dropping and maintains apical dominance.
What is the function of Gibberellins?
Stimulates seed germination, stem elongation and pollen tube growth in fertilisation.
What is the role of abscisic acid?
Stimulates stomatal closing and maintains seed dormancy. High levels of this may be maintained by auxin.
What are the role of Cytokinins?
They override apical dominance, allowing bud growth.
What is the commercial use of ethene?
To control fruit ripening. Fruit picked before ripened, exposed to ethene at end of transportation to quickly ripen.
Preserves cut flowers/green veg.
What is the commercial use of rooting pwders?
Micropropagation to stimulate root growth and producing seedless plants as they cannot reproduce themselves.
Auxins in it also stimulates shoot growth through apical dominance.
What hormone is in weed killers and how to do they work?
Synthetic auxins applied to leaves promoting growth of broad leaved weeds so much they can’t support it and die.
This leaves the narrow leaved crops to grow without competition.
Cheap and less harmful to environment than pesticides.
What are gibberellins commercially used for?
Germination of seeds used in beer brewing to produce malt.
Stem elongation.
What is the commercial use of cytokinins?
Prevent ageing in ripened fruits and aid fruit dropping.
