Plant Hormones and Tropisms Pt. 2 Flashcards
1
Q
unequal growth due to contact with solid objects
A
thigmotropism
2
Q
Greek words for thigmotropism
A
Thigma, tropos
3
Q
Thigma means
A
touch
4
Q
example of thigmotropism
A
coiling of tendril
5
Q
grows straight until it touches something, then the cells in contact with an object, grow less while those on the opposite side elongate
A
flowering plant
6
Q
can be quite rapid; a tendril has been observed to encircle an object within 10 minutes
A
thigmotropism
7
Q
can bring about a response that lasts for several days
A
thigmotropism
8
Q
thigmotropism can be delayed in the dark, and this will only respond when illuminated
A
tendrils
9
Q
after the transfer of a phosphate group from ATP to the photoreceptor, what happens to the photoreceptor
A
triggers a transduction pathway, in some unknown way, leads to the entry of auxin into the cell
10
Q
rather than light can cause thigmotropism, therefore the need for light may simply be a need for ATP
A
adenosine triphosphate (ATP)
11
Q
touch response related to thigmotropism but the entire plant responds to the presence of environmental stimuli, such as wind or rain
A
thigmorphogenesis
12
Q
what happens to a tree growing in a windy location
A
shorter, thicker trunk
13
Q
such as rubbing a plant with a stick can inhibit cellular elongation a produce a sturdier plant with increased amounts of support tissue
A
mechanical simulation
14
Q
dependent on turgor pressure changes in plant cells
A
turgor movements
15
Q
do not involve growth and are not related to the source of the stimulus
A
turgor movements
16
Q
turgor movements can result from
A
touch
shaking
thermal simulation
17
Q
a sensitive plant which has compound leaves, meaning that each leaf contains many leaflets
A
mimosa pudica (makahiya)
18
Q
has a progressive response to the stimulus that takes only a second or two
A
mimosa
19
Q
thickening, a portion of flowering plant that is involved in controlling turgor movement
A
pulvinus
20
Q
lose potassium ions and then water follows by osmosis that causes the leaf folding
A
motor cells
21
Q
what happens to the leaflets of the leaf when the pulvinus cells lose turgor
A
collapse
22
Q
cause the response to move from one leaflet to another after a leaflet collapse
A
electrical mechanism
23
Q
speed of electrical charge measured and its transmission
A
1 cm/s
24
Q
closes its trap in less than 1 second when three hairs at the base of the trap (trigger hairs) are touched by an insect
A
venus flytrap
25
where the electrical charge is propagated in venus flytrap
lobes of the leaf
26
what causes the electrical charge that is propagated in the venus flytrap (cells near the outer region)
Cells located near the center near the outer region of the lobes rapidly secrete hydrogen ions into their cell walls, loosening them and allowing the walls to swell rapidly by osmosis
27
what causes the electrical charge that is propagated in the venus flytrap (cells in the inner portion)
The cells in the inner portion of the lobes and the midrib rapidly lose ions, leading to a loss of water by osmosis and collapse of these cells
28
examples include leaves closing at night, occur in circadian rhythms
sleep movements
29
24-hour cycles
circadian rhythms
30
circadian rhythms can be observed because at night the leaves fold upward into a shape resembling hands at prayer
prayer plant
31
plant that opens its flowers in the early part of the day and closes them at night
morning glory
32
morning glory
Ipomea leptophylla
33
in most plants, this is open in the morning and close at night
stomata
34
to qualify as circadian rhythm the activity must:
occur every 24 hours
take place in the absence of external stimuli (such as dim light)
be able to reset if external cues are provided
35
the internal mechanism by which a circadian rhythm is maintained in the absence of appropriate environmental stimuli
biological clock
36
Are synchronized by external stimuli to 24-hour rhythm
biological clock
37
the length of daylight compared to length of darkness, sets the biological clock
photoperiod
38
Also indicates seasonal changes better than temperature changes
photoperiod
39
as little no to effect in the biological clock
temperature
40
work with Arabidopsis and other organisms suggest that biological clock involves the transcription of this
clock genes
41
one model proposes that the information-transfer system from DNA to RNA to enzyme to metabolite, with all of its feedback controls, is intrinsically what and could be the basis for biological clocks
cyclical
42
describe the information transfer system (DNA -> metabolite)
DNA -> RNA -> Enzyme -> Metabolite
43
control sleep movements, the opening and closing of stomata, the discharge of floral fragrances, and the metabolic activities associated with photosynthesis
genes
44
also influences seasonal cycles that depend on day/night lengths, including the regulation of flowering
biological clock
45
outwardly very similar in all species
circadian rhythms
46
not the same in all species
clock genes
47
many physiological changes in flowering plants are related to this in day length
seasonal change
48
example of physiological change in flowering plants related to seasonal changes
seed germination
breaking of bud dormancy
onset of senescence
49
a physiological response prompted by changes in the length of day or night in a 24-hour daily cycle
photoperiodism
50
in some plants, photoperiodism can influence what
flowering
51
flowers in the spring
violets
tulips
52
flowers in the fall
goldenrod and asters
53
requires the participation of a biological clock (can measure time), and activity of a plant photoreceptor (phytochrome)
photoperiodism
54
measure time
biological clock
55
Greek words for photoperiodism
photos and periodus
56
photos mean
light
57
periodus means
course
58
blue-green leaf pigment that is present in the cytoplasm of plant cells
phytochrome
59
Greek words for phytochrome
phyton chroma
60
phyton means
plant
61
chroma means
color
62
composed of two identical proteins
phytochrome
63
portion of the phytochrome where the light-sensitive region is located
larger portion
64
can be said to act like a light switch because, like a light switch, it can be in the down (inactive) position or in the up (active) position
phytochrome
65
prevalent in daylight that activates phytochrome, and it assumes its active conformation known as Pfr
red light
66
active conformation of phytochrome
Pfr
67
when it moves to the nucleus, it interacts with specific proteins, such as a transcription factor
Pfr
68
activates certain genes and inactivates others (phytochrome)
Pfr and transcription factor
69
active form of phytochrome is called this way because it absorbs far-red light.
Pfr
70
prevalent in the evening and it serves to change Pfr to Pr
far red light
71
inactive form of phytochrome
Pr
72
a conversion cycle that is known to control various growth functions in plants
Pr -> Pfr
73
promotes seed germination and inhibits shoot elongation
Pfr
74
indicates to some seeds that sunlight is present and conditions are favorable for seed germination
prescence of far red
75
Reason why some seeds are only partly covered with soil when planted
to expose and activate Pfr
76
plants inhibited by light, so they must be planted deeper
arabidopsis seeds
77
what happens to seedlings that grow in the dark characterized by the: shoots increasing in length and leaves remaining small
etiolate
78
only when this happen does the seedling grow normally
conversion of Pr to Pfr
79
Flowering plants can be divided into three groups on the basis of their flowering status:
short-day plants
long-day plants
day neutral plants
80
flower when the day length is shorter than a critical length
short day plants
81
example of short day plants
cocklebur
goldenrod
poinsettia
chrysanthemum
82
length is longer than a critical length
long day plants
83
long day plants
wheat
barley
rose
iris
clover
84
are not dependent on day length for flowering
day neutral plants
85
example of day neutral plants
tomato
cucumber
86
criterion for designating plants as short-day or long-day
critical number
87
has a critical length of 14 hours
spinach
88
scientists discovered that it will not flower if required long dark period is interrupted by a brief flash of white light
cocklebur
89
will flower if an overly long dark period is interrupted by brief flash of white light
long day plant
90
which length controls flowering
length of dark period
91
when night is longer than a critical length, this kind of plant flowers
short day plant
92
The plant does not flower when the night is shorter than the critical length
short day plant
93
Does not flower if the longer-than-critical-length is interrupted by flash of light
short day plant
94
When the night is shorter than critical length, clover flowers
long day plant
95
The plant does not flower when the night is longer than a critical length
long day plant
96
does flower when a slightly longer-than-critical-length night is interrupted by a flash of light
long day plant
97
irreversible changes in cell size and plant organs due to cell enlargement and division
growth
98
transition from embryonic stages up to its later stages in maturation.
development
99
development includes the following:
growth
morphogenesis
differentiation
100
kind of growth wherein an organism stops growing as it reach a certain size
determinate
101
a kind of growth wherein cell keeps on dividing indefinitely
indeterminate
102
refers from the activity of apical meristems in which cell division is followed by progressive cell enlargement, typically elongation
primary growth
103
involves two lateral meristems: the vascular cambium and the cork cambium
secondary growth
104
gives rise to secondary xylem and phloem
vascular cambium
105
produces the periderm, consisting of many cork cells
cork cambium
106
lateral meristem that gives rise to the secondary xylem and secondary phloem
vascular cambium
107
external factors that affect growth
sunlight
wind
gravity
water
108
responses to environmental stimuli
tropic
nastic
taxis
109
growth response oriented with regard to the stimulus
tropic
110
stereotyped nongrowth response that is not oriented with regard to the stimulus
nastic
111
– response in which a cell swims toward (positive ) or away (negative) a stimulus
taxis
112
example of tropic response
phototropism
gravitropism
thigmotropism
chemotropism
113
nastic responses
photonasty
thigmonasty
nyctinasty
thermonasty
114
organic chemicals produced in one part of the plant and then transported to other parts, where they initiate a respond
plant hormones
115
identify the hormone:
abscission suppression
apical dominance
cell elongation
root formation in cuttings
auxin
116
identify the hormone
-bud activation
- cell division
- fruit/embryo development
- prevents leaf senescence
cytokinin
117
-converts some juveniles into adult condition and vice versa
- release seed from dormancy
- stem elongation
- stimulates pollen tube growth
gibberellins
118
-initiation of dormancy
- resistance to stress condition
- stomatal closure
abscisic acid
119
-fruit ripening and abscission
- initiation of root hairs
- latex production
- formation of aerenchyma in submerged roots
ethylene
120
level of organization where plant responses that promote survival and reproductive success have evolved through natural selection
species level
121
level of organization where some part or the entire plant responds to a stimulus
organismal level
122
level of organization where receptors receive signals, transduction pathways transform them, and genes or metabolic pathways react to them
cellular level
123
use a reception-transduction-response pathway when they respond to a stimulus
flowering plants
124
involved in phototropism and gravitropism. When a plant is exposed to light, auxin moves laterally from the bright to the shad side of the stem
auxin-controlled cell elongation
125
causes stem elongation between nodes.
giberellin
126
After this hormone binds to a plasma membrane receptor, a DNA-binding protein activates a gene leading to the production of amylase
giberellin
127
an enzyme that speeds the breakdown of amylase
amylase
128
cause cell division, the effects of which are especially obvious when plant tissues are grown in culture
cytokinin
129
two plant growth inhibitors
ABA and ethylene
130
well known for causing stomata to close
ABA
131
known for fruits to ripen
ethylene
132
when flowering plants respond to stimuli this occurs
growth and/or movement
133
growth responses toward or away a unidirectional stimuli
tropism
134
not directional
nastic movements
135
due to this some parts respond to touch and some perform sleep movement
turgor pressure
136
believed to be controlled by a biological clock
circadian rhythms
137
pigment involved in photoperiodism, the ability of plants to sense the length of the day and night during a 24-hour period
phytochrome
138
phytochrome activation can lead to
seed germination
shoot elongation
flowering of plants
139
causes phytochrome to exist as Pfr
day light (red light)
140
phytochrome during the night can be reconverted to this by metabolic processes
Pr
141
flower only when the days are shorter than a critical length
short day plants
142
flower only when the days are longer than a critical length
long day plants
143
have defenses against predators and parasites
flowering plants
144
routinely produced that protects plants from herbivores, particularly insects
secondary metabolites
145
causes plants to produce systemin
wounding
146
travels about the plant and causes cells to produce proteinase inhibitors that destroy an insects digestive enzymes
systemin
147
plants have permanent relationships with them, will attack predators
ants
