Homeostasis: plant hormones

Question 1

What is a hormone

Answer 1

a chemical compound produced in one part of the plant that controls growth activity in another part of that plant

Question 2

What are auxins

Answer 2

stimulate the elongation of plant cells. important in plant responses to light and gravity

Question 3

What are cytokinins

Answer 3

promote cell division by stimulating the production of the proteins needed for mitosis and cytokinesis. also delay aging of leaves and fruit

Question 4

What are gibberellins

Answer 4

stimulate plant growth by changing the plants cell walls, stop dormancy in seeds so they will begin to germinate, and can reverse genetic dwarfism in plants

Question 5

What are ethlylene

Answer 5

the only known gaseous hormone, mainly affects the ripening of fruits. ethylene weakens the cell walls of unripe fruits and breaks down complex carbohydrates (starches) into simple sugars (sucrose and fructose) . Because ripe fruits and vegetables are bruised easily during shipping, growers often pick and ship unripe fruits and vegetables. once they reach their destinations, a treatment with ethylene is used to speed up the ripening process

Question 6

What is abscisic acid (ABA)

Answer 6

a plaant hormone that generally prevents growth (of bud and shoot) it blocks the intake of carbon dioxide by controlling the opening and closing of leaf stomata. (can be important during droughts to conserve moisture). it maintains seed dormancy

Question 7

What is ripening positive feedback

Answer 7

A ripening apple releases a gaseous plant hormone ethylene (the stimulus). ethylene accelerates the ripening of unripe fruit in its vicinity so nearby fruit also ripens, releasing more ethylene (the response). all the fruit quickly ripen together