Lecture 25: Plant Hormones

Question 1

_____ are chemical signals that regulate and control almost every biological process

Answer 1

plant hormones

Question 2

plant hormones are produced in ____ quantities but have ____ roles within the plant

Answer 2

1. small
2. specific

Question 3

_____ are mobile throughout the entire plant

Answer 3

plant hormones

Question 4

what are the three steps of sending signals with plant hormones?

Answer 4

1. reception outside cell wall
2. transduction and amplification from relay proteins and secondary messengers within cell
3. activation of cellular responses

Question 5

what are the five major plant hormones?

Answer 5

auxin, cytokinins, gibberellins, abscisic acid, ethylene

Question 6

_____ is the hormone that initiates growth

Answer 6

auxin

Question 7

____ is the hormone that initiates division

Answer 7

cytokinins

Question 8

____ is the hormone that initiates cell elongation/expansion

Answer 8

gibberellins

Question 9

____ is the hormone that initiates fruit maturation and is a stress hormone

Answer 9

abscisic acid (ABA)

Question 10

____ is the hormone that is a gaseous stress response

Answer 10

ethylene

Question 11

where is auxin synthesized?

Answer 11

in SAM and young leaves

Question 12

_____ promotes vertical growth

Answer 12

auxin

Question 13

what happens when you limit or remove auxin synthesis in a plant?

Answer 13

more lateral growth, plant can’t grow upwards

Question 14

where is cytokinins produced?

Answer 14

actively growing tissues (roots, embryos, fruits)

Question 15

_____ is a hormone that opens the stomata

Answer 15

cytokinins

Question 16

apical dominance is controlled by ____, ____, and ____

Answer 16

auxin, cytokinins, and strigolactone

Question 17

what happens if you downregulate cytokinin?

Answer 17

less branches

Question 18

what happens if you upregulate cytokinin?

Answer 18

more roots than shoots!

Question 19

what happens if you cut off the SAM?

Answer 19

no more auxin, only lateral growth

Question 20

where is gibberellins produced?

Answer 20

in meristems, roots, young leaves, developing seeds (actively growing areas)

Question 21

_____ signals seeds to germinate when released from embryo i.e releases seed from dormancy

Answer 21

gibberellins

Question 22

_____ is involved with leaf senescence (browning and death)

Answer 22

abscisic acid

Question 23

____ is a hormone that closes the stomata (which enables plants to withstand drought), maintains seed dormancy, involved in stress response

Answer 23

ABA

Question 24

which hormone can affect other plants/fruits around it? why?

Answer 24

ethylene, because its gaseous