Ch. 39 A

Question 1

What is etiolation?

Answer 1

Morphological adaptations for growing in darkness

Question 2

Etio

Answer 2

Cause

Question 3

What is de-etiolation?

Answer 3

After exposure to light, a plant (ex. potato) will go changes and grow normally

Question 4

phyto

Answer 4

plant

Question 5

chrome

Answer 5

color

Question 6

What causes receptor protein to change shape?

Answer 6

Response to stimulus
Ex. Phytochrome capable of detecting light which causes de-etiolation

Question 7

What are second messangers?

Answer 7

Transfers and amplify signals from receptors to other proteins that cause responses

Question 8

what are examples of secondary messangers?

Answer 8

Ex. calcium ions and cyclic GMP

Question 9

What does the phytochrome receptor respond to and what does it do?

Answer 9

Respond to light and:
1) opens Ca channels, Increases Ca levels in cytosol
2) Activates an enzyme to produce cGMP

Question 10

Phytochrome

Answer 10

Plant color

Question 11

What reaction causes GMP to turn into Cyclic GMP

Answer 11

Dehydration Synthesis

Question 12

kin

Answer 12

movement

Question 13

Ase

Answer 13

Enzyme

Question 14

What are kinases?

Answer 14

Enzymes that catalyze the transfer of a phosphate group from ATP to a specified molecule

Question 15

Responses to stimulation that involve changes in activity of enzymes can occur by?

Answer 15

1) Transcriptional Regulation
2) Post-translational modification

Question 16

What does Post-translational modification involve?

Answer 16

Modifications of existing proteins in the signal response

Question 17

Common Modifications of Post-translational modification are

Answer 17

1) Phosphorylation of specific amino acids
2) Secondary messengers activate protein kinases directly

Question 18

How do protein kinases often work?

Answer 18

Cascade linking initial stimuli to gene expression through phosphorylation of transcription factors

Question 19

Phosphorylation

Answer 19

Activation, addition of phospate group

Question 20

Dephosphorylation

Answer 20

inactivation, remove phosphate group

Question 21

How does Transcriptional Regulation work

Answer 21

Specific transcription factors bind directly to specific regions of DNA and control transcription of specific genes

Question 22

Are transcription factors activators or repressors?

Answer 22

They are both, they can increase or decrease transcription of a specific gene

Question 23

De-etiolation activates enzymes that? (3)

Answer 23

1) Function in photosynthesis
2) Supply chemical precursors for chlorophyll production
3) Affect the levels of plant hormones that regulate growth

Question 24

What are plant hormones?

Answer 24

Chemical signals that modify or control one or more specific physiological processes within a plant
Also known as plant growth regulators

Question 25

Growth promoters (3)

Answer 25

1) Auxins 2) Cytokinins 3) Gibberellins

Question 26

Growth inhibitors (2)

Answer 26

Ethylene Abscissic Acid

Question 27

Are plant hormones produced in high or low concentrations?

Answer 27

LOW but has huge effect on growth and development

Question 28

Each hormone: multiple hormones:

Answer 28

Each hormones have multiple effects Multiple hormones can influence a SINGLE process

Question 29

plant responses depend on what _______ and _______ of hormones?

Answer 29

1) concentration of specific hormones 2) combination of present hormones

Question 30

Extra hormones to know

Answer 30

Brassinosteroids Jasmonates Strigolactones

Question 31

What is a tropism?

Answer 31

Any response resulting in curvature of organs toward or away from stimulus

Question 32

Examples of tropism (3)

Answer 32

1) Phototropism 2) Thigmotropism 3) Gravitropism

Question 33

What is auxin?

Answer 33

Any chemical that promotes elongation of coleoptlies

Question 34

What is Indoleacetic acid?

Answer 34

Common auxin in plants also known as IAA think in-dole-acetic acid

Question 35

Is transport of auxin polar or nonpolar?

Answer 35

Polar Produced in shoot tips and transported down stem

Question 36

What are auxin transporter proteins?

Answer 36

Move hormone from basal end of one cell into the apical end of the neighboring cell

Question 37

explain the effect of gravity on the direction of auxin

Answer 37

NO EFFECT

Question 38

What is the role of auxin in cell elongation?

Answer 38

1) Auxin stimulates proton pumps in the plasma membrane (ACID GROWTH HYPOTHESIS) 2) Causes pH level to drop and increase membrane potential

Question 39

What does reduced pH cause?

Answer 39

Activates expansins, enzyme that loosens fabric of the cell wall

Question 40

What does osmotic of water into cell cause

Answer 40

Increased turgor pressure

Question 41

What does cell wall plasticity and increased turgor pressure enable

Answer 41

Causes cell to elongate

Question 42

Acid growth

Answer 42

Loosens cell wall which allows cell to passively elongate

Question 43

What happens when reduced auxin flow is caused from the shoot?

Answer 43

Stimulates growth in lower branches

Question 44

What is phyllotaxy

Answer 44

The arrangement of leaves on the stem Auxin plays a role in this

Question 45

What determines leaf venation pattern?

Answer 45

Polar transport of auxin from margins

Question 46

What is controlled by auxin?

Answer 46

1) Activity of the vascular cambium (transport) 2) Organization of female angiosperm gametophytes (maybe)

Question 47

Activity of the vascular cambium is controlled by what hormone?

Answer 47

auxin

Question 48

Use of indolebutyric acid (IBA)?

Answer 48

1) Stimulates adventitious roots 2) Used in vegetative propagation of plants by cuttings

Question 49

Use of synthetic auxins?

Answer 49

Used as herbicides such as 2,4-d (weed killer) kills eudicots by hormonal overdose (monocots can inactivate the hormones)

Question 50

What promotes fruit development

Answer 50

Auxin Seeds produce auxin to make fruits

Question 51

What are cytokinins?

Answer 51

hormone that stimulates cytokinesis

Question 52

Where are cytokinins produced?

Answer 52

Growing tissues such as roots, embryos, and fruits

Question 53

What do cytokinins control

Answer 53

Cell division and differentiation with the help of auxin

Question 54

What is apical dominance?

Answer 54

The terminals bud's ability to suppress development of axillary buds

Question 55

What controls apical dominance? (4)

Answer 55

1) Sugar 2) cytokinins 3) auxin 4) strigolactone

Question 56

What does removal of apical bud do? (3)

Answer 56

1) increases sugar availability 2) decreases auxin and strigolactone levels 3) initiates axillary bud growth

Question 57

How does cytokinins slow aging of plant organs? (3)

Answer 57

1) inhibiting protein breakdown 2) stimulating RNA and protein synthesis 3) mobilizing nutrients from surrounding tissues