unit 2: plants Flashcards
(184 cards)
1
Q
services of plants
A
food, natural products, ecosystem services, culture,
2
Q
group of plants that produce flowers, more recently evolved, largest group of plants
A
angiosperms
3
Q
when did the invasion of land plants begin
A
475 Ma
4
Q
challenges to land invasion of plants
A
maintain water in cells, structure, reproduction
5
Q
what advantage led to land invasion
A
less competition for light
6
Q
ancestor of land plants
A
green algae (charophyte)
7
Q
traits of algaeshared with land plants
A
cellulose cell wall, chlorophyll a and b, sperm with anterior flagella,
8
Q
traits allowing for land invasion
A
spores covered in sporopollenin, dispersal by wind, fresh water
9
Q
charophyte life cycle
A
diploid zygote undergoes meiosis to create spores, leading to adult algae through mitosis
10
Q
most stable bipolymer, decay resistant, dehydration resistant, UV protectant
A
sporopollenin
11
Q
essential for acquiring nutrients, transformed land surface
A
mycorrhizal fungi
12
Q
broke down rocks, died in soil (organic matter)
A
soil led to rivers which led to nutrients in oceans
13
Q
arose in 425 Ma, caused rapid adaptation for life on land
A
vascular plants
14
Q
slows water loss, inhibits gas exchange, stromata/pores needed
A
cuticle
15
Q
major adaptations shared by all land plants
A
cuticle, pores/stromata, embryo
16
Q
alternation of generations in life cycle
A
zygote undergoes mitosis to create sporophyte, then meiosis to spores, then mitosis to gametophyte
17
Q
young sporophyte nourished by maternal tissue
A
embryo
18
Q
liverworts, mosses, and hornworts, gametophyte dominant
A
bryophyte
19
Q
what does a dominant gametophyte mean
A
sporophyte lives on and depends on gametophyte
20
Q
sporophytes became larger and more complex as
A
vascular system was acquired
21
Q
why did sporophyte dominance develop
A
so plants could grow taller (spore dispersal) and because gametophytes are constrained by water needs
22
Q
sporophyte and gametophyte are independent
A
ferns
23
Q
sporophyte dominant, involves conifers
A
gymnosperms
24
Q
rely on soil water, actively control hydration, allow for bigger size, can carry out PS in dry conditions
A
vascular plants
24
outer layer of cells, protective
epidermis
25
major organ types of vascular plants
leaves, reproductive organs, stems (make up shoot) and roots
26
transports water through low resistance pathway
xylem (vascular tissue)
27
transports sugars
phloem (vascular tissue)
28
everything not epidermal or vascular tissue
ground tissue
29
common ground tissue
parenchyma, performs metabolism
30
cells lack cytoplasm and membrane, conduits, vessels, pits, angiosperm have higher transport capacity
xylem features
31
how water is pulled through xylem
evaporative pump
32
land, embryo, alternation of generations, stromata, cuticle
features of all land plants
33
long lives sporophyte, vascular system
ferns, gymnosperms, angiosperms
34
seeds
gymnosperms and angiosperms
35
flowers
angiosperms
36
order of trait evolution
alt of gens, stromata, long lives sporophyte, vascular system, seeds, flowers
37
ecologically dominate, ovules and seeds enclosed in sporophyll, double fertilization
angiosperms
38
major innovation allowing sporophyte dominance
seed,
39
female gametophyte of angiosperms
stays on sporophyte
40
male gametophyte of angiosperms
becomes pollen grain
41
delivers male gametophyte (sperm) to female gametophyte
pollination
42
embryo and food supply
seed
43
where is pollen delivered to
ovule
44
angiosperm pollen delivery
pollen goes into carpel tissue (ovule encased in sporo carpel)
45
why are seeds better than spores
seed remain dormant until environment is favorable, seeds have food supply, seeds can be transported by animals
46
do seed plants make spores
yes, but they are not dispersed, become gametophytes
47
fertilized ovule
seed
48
structure derived from ovary, encloses seed
flower
49
ovary, style, and stigma
pistil (female)
50
female gametophyte make up
7 cells, 8 nuclei
51
where male gameophyte is made
anther and filament (stamen)
52
sporophyll with pollen sacs containing pollen
stamen
53
male gametophyte make up
3 cells, creates 4 spores and 4 gametophytes each
54
path of pollen
stigma, style, ovules
55
triploid cell created in double fertilization
endosperm
56
spore undergoes what process to become gametophyte
mitosis
57
ovule undergoes what to become seed
fertilization
58
ovary and carpel tissue undergo what to become fruit
fertilization
59
what happens when pollen touches appropriate stigma
travels pollen tube
60
grow down style, find egg cell
pollen tubes
61
unique to angiosperm
double fertilization
62
pollen tube delivers one sperm to egg creating
zygote and embryo
63
other sperm delivered to two polar nuclei creating
endosperm
64
nutritive tissue that feeds embryo
endosperm
65
contains 2 cotyledons
eudicots
66
contains 1 cotyledon
monocot
67
contain meristem tissue, involved in primary growth
apical and axillary bud
68
elongates shoots and roots, produces leaves and reproductive structures
primary growth
69
is plant growth indeterminate (stops at a size)
no
70
determined by location
plant cell function
71
do zones stay with the tip?
yes
72
zones from top to end of tip
zone of differentiation, zone of elongation, zone of cell division
73
uptakes water and nutrients
roots
74
what type of tissue does primary growth form
vascular, ground, dermal
75
examples of dermal tissue
epidermis, guard cells, lower epidermis
76
examples of ground tissue
mesophyll, bundle sheath cell, pith, cortex
77
examples of vascular tissue
vascular bundle, xylem, phloem, vein,
78
does secondary growth occur in monocots
no
79
what happens in secondary growth
a secondary xylem and phloem forms, a cork cambium forms to create bark,
80
positive tropism
towards stimuli
81
negative stimuli
away from stimuli
82
heliotropism
light stimuli, grows toward
83
thigmotropism
touch stimuli
84
signal transduction pathway of tropisms
reception, relay proteins and secondary messengers, activation of responses
85
cells on shaded side elongate faster, curves toward light
phototropism
86
protein that is stimulated by blue light, leading to signals for phototropism
phototropin
87
shade results in
differential activation of phototropin
88
indoleactic acid, transmits signals, constantly made while tip growing, when light from side, differential activation
auxin
89
auxin binds to receptor that stimulates membrane bound proton pump, cell wall becomes more acidic, low pH activates expansins, separates polysaccharides, expansin increases cell wall extensability, osmosis draws water into cell, cell expands
acid growth hypothesis
90
rings in trunk correlate with
tree age
91
senses light in tip of plant
phototropin
92
if no auxin present
no cell expansion (division but not elongation)
93
process instigated by changes in hormone concentration, response to changes in light and temperature
leaf abscission
94
chlorophyll production stops, nutrients and sugars moved to stem and roots for storage, cells divide but don't expand
leaf abscission
95
present in green leaves
chlorophyll
96
present in yellow leaves
xanthaphylls
97
present in orange leaves
carotenes
98
aid in light absorption during photosynthesis
carotenoids
99
are colors of yellow and orange always the same
yes
100
present in red leaves
anthrocyanins
101
conditions that favor photosynthesis
increase brilliance of red
102
only tannins left in leaves
brown leaves
103
cells divide but don't expand, cells walls broken down, cells begin to separate,
leaf abscission
104
primary purpose is absorption of light and CO2 for PS
leaves
105
reasons leaves are thin
diffusion difference shorter for CO2, more light absorbed,
106
60 percent of mesophyll, little air volume, lots of chloroplasts
palisade mesophyll
107
40 percent of mesophyll, lots of air volume, fewer chloroplasts
spongy mesophyll
108
which type of mesophyll is used more for photosynthesis
palisade
109
why is spongy mesophyll present
diffuses CO2 faster
110
why did the structure of leaves evolve
to maximize absorption of light in the wavelengths that drive PS
111
allows leaves to regulate water loss and carbon gain
stromata
112
restricts water loss from leaves but inhibits CO2 uptake
cuticle
113
light reflecting back into palisade mesophyll from spongy
backscatter
114
the greater number of air water interfaces in spongy mesophyll allows for more
light absorption in palisade chloroplasts
115
what adds most of plant mass
CO2
116
where do light reactions and the calvin cycle occur
chloroplast
117
what does the calvin cycle produce
NADP, ADP, and sugars
118
what do light reactions produce
ATP, NADPH, and oxygen
119
what is needed for a light reaction
light and water
120
occurs in stroma, creates sugars
calvin cycle
121
what fixes inorganic CO2 into a biochemical molecule
rubisco
122
what reactions use rubisco
calvin cycle and photorespiration, fix carbon and oxygen respectively
123
why is photorespiration not efficient
fixes oxygen, decreases amount of sugar made per light absorbed, happens under stress
124
why does rubsico fix oxygen
evolved a ta time of high CO2
125
separates light reactions and calvin cycle, mesophyll (PEP C) and bundle sheath (rubisco), good for high light, dry env
C4 photosynthesis
126
steps of C4 PS
PEP C fixes CO2 in mesophyll, organic acid moved to bundle sheath, rubsico fixes CO2, calvin cycle
127
what does C4 PS eliminate
photorespiration
128
C4 benefits
high PS capacity, high yield, high water use efficiency
129
C4 drawbacks
CO2 pump costs lots of ATP
130
do all plants do C3 PS
YES
131
separated temporally, similar to C4
CAM PS
132
CO2 stored at night, occurs in one cell, eliminates photorespiration, good for dry, hot environments
CAM PS
133
3 common types of CAM plants
desert, epiphyte, aquatic
134
in CAM, when doe rubisco work
day
135
do all plants have bundle sheath cells
yes
136
how does CAM take CO2 at night
PEP C
137
what does water hydrogen bonding allow
universal solvent, cohesive, adhesive
138
method of water transport, high to low conc, occurs due to random molecule movement, no membrane necessary
diffusion
139
method of water transport, driven by pressure gradient, transport over large distances
mass flow
140
specialized diffusion over selectively permeable membrane, water potential determines direction of movement
osmosis
141
equation for water potential
potential = pressure potential + solute potential
142
water moves from high potential to
low potential
143
solute potential becomes more negative as
solutes become more concentrated
144
what is the equilibrium water potential of two small cells
the average of both water potentials
145
why do plants need water
photosynthesis, expand and grow cells, transpiration
146
what is the WP of a small cell at equilibrium in a big beaker
the WP of the beakers
147
evaporation of water out of stomata, provides transport of nutrients from roots to leaves, cools leaves, allows stomata to stay open for CO2 absorption
transpiration
148
what percent of water is used for transpiration
95 percent
149
drives flow of water out of leaf
vapor pressure difference
150
pressure exerted by a vapor on a liquid
vapor pressure
151
low humidity means
low vapor pressure
152
partial pressure of water vapor over saturated (possible) vapor pressure
relative humidity
153
where is vapor pressure always higher
inside the leaf, evaporates out
154
VP inside leaf - VP outside leaf
VPD
155
lower relative humidity will
increase VPD
156
stomatal conductance
how many and how open stomata are
157
what determines how open stomata are
guard cells
158
steps of guard cells opening stomata
make ATP in chloroplasts through PS, use to pump protons out, ions taken up creating gradient, solutes accumulate, decreasing WP, osmotic water uptake, cell swells opening stomata
159
is stomata opening energy dependent
yes
160
increasing CO2 concentration means
stomata close (low conc is when open and lots of PS)
161
increasing VPD means
stomata close (dry air)
162
increased leaf temp means
stomata open until too hot
163
increased light means
stomata open
164
dryer soil means
stomata closed
165
how much water is needed for transpiration
a LOT
166
increased plant size means
increased water needed
167
what cells move water
xylem cells (trachids and vessels in conduits)
168
tracheids and vessels of xylem
are dead when functioning, have 2 cell walls, elongated
169
how is water moved from roots to leaves
pulled along a gradient in negative pressure potential
170
water within a plant is
in a continuous network
171
how is water held up
surface tension of tiny menisci that form in microfibrils and adhere water to cellulose, forms water columns from xylem to evaporation site
172
what forms a negative pressure at the site of evaporation
a pointy meniscus, means stomata open
173
where does water travel to
site of evaporation through mass flow driven by the negative gradient
174
cohesion tension theory
drop in pressure potential creates a gradient in the plant, potential is highest near soil, lowest at top of plant
174
how is cohesion involved
cohesion keeps water columns intact
174
highest to lowest pressure potential of plant
soil, root, stem, leaf, atmosphere
175
why do plants need phloem
to move sugars from leaves to other parts
176
what does the phloem move
low weight sugars, oligosaccharides (photosynthates)
177
why are low weight sugars good
strong impact on solute potential, soluble in water, stable
178
examples of sources for phloem sugars
leaves, PS stems, storage in cells and roots
179
examples of phloem sinks
roots, developing leaves, reproductive structures, stems, meristems
180
parts of phloem
sieve tubes and ccells
181
sieve tubes and cells
are alive, have cell membrane, thick walls, elongated, very modified cytoplasm (no nucleus)
