BIO FINAL EXAM CH. 39 PLANT HORMONES

Question 1

What is the source of the plant hormone AUXIN

Answer 1

Stem apical meristems & young leaves
- one way polar transport (tip -> base)

Question 2

What are the two major effects of the plant hormone Auxin

Answer 2

• cell elongation, acid growth hypothesis
• interacts with other hormones

Question 3

Aging leafs produce _____ and more _____

Answer 3

less auxin and more ethylene

Question 4

What is Auxins practical use?

Answer 4

stimulates growth of adventitious roots & promotes fruit development.

Question 5

What is the source of the plant hormone CYTOKININS.

Answer 5

Roots some in embryos or fruits.

Question 6

What are the three major effects of the plant hormone CYTOKININS.

Answer 6

• stimulate cytokineses (cell division)
• anti-aging
• interacts with auxins to control cell division, differentiation and apical dominance.

Question 7

What about Apical Dominance?

Answer 7

Removal of apical buds increase sugar availability but decreases axuxins

Question 8

What is the source of the plant hormone GIBBERELLINS.

Answer 8

apical meristems (roots & shoot), young leaves and seeds.

Question 9

What are the three major effects of the plant hormone GIBBERELLINS.

Answer 9

• stem elongation (grows straight up)
• fruit growth (makes grapes larger)
• seed germination

Question 10

What is the source of the plant hormone ABSCISIC ACID (ABA)?

Answer 10

everywhere

Question 11

What are the three major effects of the plant hormone ABA?

Answer 11

• slows growth
• seed dormancy and drought tolerance (increase the likelihood the the seed will germinate in optimal conditions.)

Question 12

What is the hormone ethylene?

Answer 12

Stress hormone in which responds to stress (drought, flooding, etc…)
produced during fruit ripening and programmed cell death.

Question 13

Ethylene is produced when

Answer 13

a seedling tip pushes against an obstacle (rock)

Question 14

What is the triple response of ethylene?

Answer 14

• slows stem elongation
• thickens the stem
• grows horizontally

Question 15

what is Senescence?

Answer 15

Programmed cell death of certain organs, or the entire plant.

Question 16

A burst of ____ is associated with onset of _____, programed cell death.

Answer 16

Ethylene, apoptosis

Question 17

What is the relationship between Auxin and Cytokinin?

Answer 17

• stem apical dominance
• auxin< shoot buds develop
• auxin> roots

Question 18

What is the relationship between Auxin and Gibberellin?

Answer 18

• Fruit development

Question 19

What is the relationship between Auxin and Ethylene?

Answer 19

Leaf abscission (detachment of parts of the leaf)

Question 20

What is the relationship between Gibberellins and ABA?

Answer 20

• seed germination

Question 21

Reversible phytochrome system

Question 22

Flashes of light at night… what happens… why?

Question 23

Plants response to gravity is called?

Answer 23

gravitropism.
- roots show positive tropism and grow downward.
- shoots show negative gravitropism and grow upward.

Question 24

Plants may detect gravity by the settling of

Answer 24

Statoliths

Question 25

What is thigmomorphogenesis

Answer 25

mechanical disturbances changes a plants form such as rubbing a young plants stems makes them shorter.