organismal bio Flashcards
(262 cards)
1
Q
eukaryote
A
cells with linear chromosomal DNA packed into a membrane enclosed nucleus
contain membrane enclosed organeless (mitochondia and/or plastids)
1
Q
prokaryotes
A
cells that have no nucleus and no membrane-enclosed organelles
DNA contained in a circular chromosome (plasmids)
2
Q
anaerobe
A
metabolism without oxygen
3
Q
aerobe
A
metabolism with oxygen
4
Q
phototroph
A
organisms that get energy from light—not all photoautotrophs do oxygenic photosynthesis
5
Q
chemotroph
A
energy that comes directly from chemical rxns
6
Q
autotroph
A
organism that generates their own food from inorganic molecules
7
Q
heterotroph
A
consumes food produced by other organisms
8
Q
plasmid
A
small, circular, double stranded DNA molecule that carries accessory genes separate from those of a bacterial chromosome
9
Q
binary fission
A
cell that doubles in cell that then splits into 2 cells
method of asexual reproduction
NO MITOSIS in prokaryotes
10
Q
stromatolite
A
layers of rock that results from the activities of prokaryotes that bind thin films of sediment(ed) minerals together
11
Q
plastid
A
family of closely related organelles including chloroplasts; found in photosynthetic eukaryotes
12
Q
cyanobacteria
A
1st photoautotrophs that capture light energy thru oxygenic photosynthesis
13
Q
endosymbiosis
A
a relationship between two species in which one organism lives inside the cell or cells of another organism
ex: mitochondria and plastids
14
Q
microbiome
A
refers to all microorganisms found in a given well-defined habitat
the collection of microorganisms living in or on an organism’s body along with their genetic material
15
Q
horizontal transmission
A
acquired from the environment
16
Q
vertical transmission
A
passed down directly from parent to offspring
ex: germline transmission of intracellular symbionts; acquisition during passage thru the birth canal
17
Q
heterocyst
A
a specialized cell that engages in nitrogen fixation in some filamentous cyanobacteria
18
Q
metabolite cross-feeding
A
interactions between bacterial strains in which molecules resulting from the metabolism of one strain are further metabolized by another strain
19
Q
filamentous chain
A
in some cyanobacteria like Anabaena, some cells in chain will differentiate and become heterocysts
allows spatial separation of nitrogen fixation (anaerobic) from photosynthesis (aerobic)
20
Q
biofilm
A
a surface coating colony of one or more species of microbes that engage in metabolic cooperation
mats of cells that secrete and become stuck to each other in a matrix of polysaccharides and proteins
- adheres to surface because cells are secreting sticky substances/sugars/proteins
21
Q
quorum sensing
A
if enough other microbes of the same type nearby —> a new density dependent activity is induced
cells know when the population reaches high density thru the conc of secreted autoinducer molecules
ex: bobtail squid
22
Q
autoinducer
A
pheromone that lets cells know when the population reaches a high enough density
23
Q
absorptive nutrition
A
fungi secrete enzymes to digest its food externally
24
hyphae
a single filament; one of many connected filaments
25
mycelium
network of hyphae
26
indeterminate growth
growth that occurs in fungi with no end structure
mycelium networks contribute to this bc the tips for hyphae keep extending
27
arbuscular mycorrhizal fungi
penetrates root cells and create arbuscules
- hyphae interact with roots and penetrate them; go into the cell thru the cell wall of root cells to form arbuscules and form networks inside
28
ectomycorrhizal fungi
form nets around the while root and cell surfaces within root but do not enter cells
29
spores
single cells capable of growing into an adult organism
a haploid cell in FUNGI produced (a)sexually that produces a mycelium after germination
30
meiosis
production of haploid cells from a diploid cell over 2 rounds of cell division
31
fertilization
union of haploid gametes produce a diploid zygote
32
sporogenesis
process of spore production
33
gametogenesis
process of gamete production
34
sporophyte
diploid organisms that produces spores by meiosis
35
gametophyte
haploid organisms that produces gametes by mitosis
36
fruiting body
contains spores
37
basidium
a reproductive appendage that produces sexual spores on the gills of mushrooms (club fungi/basidimycetes)
38
basidiocarp
elaborate fruiting body of a fungi
39
plasmogamy
fusion of the cytoplasm of cells from 2 individuals
occurs of stage 1 of fertilization of sexual reproduction of fungi
nuclei don’t fuse
40
heterokaryon
the nuclei during plasmogamy don’t fuse (n+n)
41
karyogamy
different haploid nuclei sharing the same cytoplasm then fuse to make the diploid zygote
42
mycosis
fungal infection
43
monophyletic group
clade/subset of the tree of life that contains all of the descendants emerging from a single common ancestor
44
ecological group
set of taxa that share common ways of life, often in a community context
45
primary endosymbiosis
1st case where something that is not photosynthetic establishes an endosymbiosis with something that is
eukaryotic cell engulfs a prokaryotic cell (e.g. cyanobacterium or other photosynthetic prokaryotes) and develops an endosymbiotic relationship with it
46
secondary endosymbiosis
rather than establishing a new endosymbiosis with a cyanobacteria, instead it establishes an endosymbiosis with a eukaryotic algal (red or green) species
47
haplodiplontic life cycle
alternating between diploid and haploid phases on a lifecycle cycle
both phases can involve mitosis
multicellular organisms in BOTH phases
48
diatom
unique glass like cell walls made of silica embedded in a matrix
diatom deposits accumulate on the ocean floor
- when tectonic plates move and fossilize them = creates diatomaceous earth
49
dinoflagellates
algae with 2 flagella, one in which is a spiral that can make them spin
dinos - whirl
50
phycocolloid
polysaccharide compounds produced by cells walls that prevent dying out/desiccation
51
lichen
an ecological group consisting of a mycobiont (heterotrophic fungus) and a photobiont (photosynthetic algae or cyanobacteria)
52
soredia
bundles of fungi and algae
in lichens, a small cluster of fungal hyphae with embedded algae
53
seed-free plant
plant does not a protected embryo
54
bryophytes
moss, liverworts, hornworts
no vascular system or seed
non vascular plant that lives on land but lacks some of the terrestrial adaptations of vascular plants
55
desiccation
drying out; removal of moisture
56
phyllids
thin leaf-like growths/tissues that absorb water through direct contact with ground or trapped moisture
where water is mostly absorbed by a bryophyte/moss
collect water from the air that’s there as humidity, fog, dew
NOT LEAVES -> LEAFS DUPE
57
rhizoids
long tubular single cell or filaments that do some water/nutrient uptake but mainly function to anchor plant
NOT ROOTS -> ROOTS DUPE
also associate with arbuscular mycorrhizal fungi
58
gametangia
new multicellular protective tissues where gametes form
multicellular plant structure in which gametes are formed
59
antheridia
gametangia that produces sperm
60
archegonia
gametangia that produce eggs
61
embryo
the zygote (fertilized egg) is also retained in the archegonium and develops embedded in and DEPENDENT on nutrition from maternal tissue
62
cuticle
waxy waterproof for sporophyte generation
provide protection
keep moisture inside their cells
63
sporangia
container
a multicellular organ in fungi and plants in which meiosis occurs and haploid cells develop
64
sporopollenin
a polymer that prevents desiccation of charophyte zygotes; make plant spores resistant to harsh environments and capable of dispersal by air
65
sporophyll
modified leaf that bears sporangia and hence is specialized for reproduction
66
sorus (pl. sori)
clustered groups of sporangia on vascular plants
on fern sporophyll
67
peat
partly decayed organic material found in huge, boggy (swamps) wetlands
extensive deposits of partially decayed organic material often formed primarily from wetland moss
68
lycophytes
club mosses, spike mosses, quillworts
leaves and roots evolved independently
leaves are microphylls with a single unbranched veins (branching only occurs at shoot tip)
69
monilophyte
ferns, horsetails, whisk ferns
leaves are megaphylls with branched veins thru leaves
potential for stem branching no limited to shoot tip
70
microphyll
a small, usually spine shaped leaf supported by a single strand of vascular tissue
only found in lycophytes
71
megaphyll
a leaf with a highly branched vascular system found in almost all vascular plants other than lycophytes
72
carboniferous period
period marked by giant plants, and by the great expansion of carbon dioxide sinks as massive amounts of carbon were sequestered as minerals
73
azolla
fairy moss, mosquito form, water fern
an aquatic fern that forms a symbiotic association with nitrogen fixing cyanobacteria that it makes a home for within pouches in its leaves
dead azolla accumulated as stagnant sediment, drawing co2 out of the atmosphere and sinking it to the ocean floor
caused cooling
azolla event:icehouse earth age with ice caps
74
heterospory
a plant species that has two kinds of spores
75
gymnosperm
naked seed
vascular plant that bears naked seeds — seeds not enclosed in protective chambers
76
seed
an adaptation of some terrestrial plants consisting of am embryo packaged along with a store of food within a protective coat
77
scales
modified leaves with sporangia
cones
they are sporophyll and part of the 2n sporophyte
78
cones
gymnosperm reproductive structures
anatomically akin to compressed fern fronts or lycophytes strobili
79
megasporangium
make megaspores that germinate to become the female gametophyte
80
megaspore
a spore from a heterosporous plant that develops into a female gametophyte
81
microsporangia
make microspores that germinate to become the male gametophyte (pollen)
82
microspore
a spore from a heterosporous plant species that develops into the male gametophyte
83
ovule
megasporangium surrounded by the protective structure that will become the seed coat
84
pollen grain
in seed plants, a structure consisting of the male gametophyte enclosed within a pollen wall
85
pollen tube
a tube that forms after germination of the pollen grain and that functions in the delivery of sperm to the ovule
86
pollination
the transfer of pollen to the part of a seed plant containing the ovules, a process that required for fertilization
87
seed coat
a tough outer covering of a seed formed from the outer coat of an ovule
flowering plants = seed coat enclosed and protects the embryo and endosperm
88
integument
layer of sporophyte tissue that contributes to the structure of an ovule of a seed plant
89
icehouse / greenhouse earth
lower co2 levels causing a big drop in global temperature that caused a long extended period with polar ice caps
90
angiosperm
container seed
a flowering plant which forms seeds inside a protective chamber (ovary)
91
determinate growth
growth in which growth stops after a certain size in reached
plant develops with a fixed endpoint
92
whorls
how flower parts are arranged on that axis in a sequential order
93
sepal
offer protection to the bud
a modified leaf in angiosperms that helps enclose and protect a flower bud before it opens
94
petals
often bright, large and attractive to pollinators
a modified leaf of a flowering plant
95
stamen
fertile organs that bear POLLEN
pollen producing reproductive organs of a flower, consisting of an anther and filament
96
filament
stalk part of the stamen that bears the anthers
97
anther
sac that contains the microsporangia where microspores form and germinate to become pollen (gametophyte)
the terminal pollen sac of a steam where pollen grains containing sperm producing male gametophytes form
98
carpel
sporophyll fused into a container within which the ovules are found
ovule producing reproductive organ of a flower (stigma, style, ovary)
99
flower
in flowers: specialized shoot with up to 4 sets of modified leaves, bearing structures that function in sexual reproduction
100
pistil
single carpel or collection of fused carpels
101
stigma
sticky surface where pollen land and pollen tube germinates; receives the pollen grain
102
style
tract down which the pollen tube migrates to reach ovules
this stalk of a flower with the ovary at the base and the stigma at the top
103
ovary
protective container around ovules
portion of the carpel in which the egg containing ovules develop
104
inflorescence
the flowering stalk
a group of flowers tightly clustered together
105
inbreeding depression
deleterious recessive mutations are exposed in offspring, lowering fitness
106
nectar guide
markings that attract and orient pollinators
107
coevolution
joint evolution of two interacting species in response to selection imposed by the other
108
pollination syndromes
suites of plant traits that suggests coevolution with a particular group
109
buzz pollination
vibration can get pollen out
ex: bumblebees vibrating their wings
110
central cell
2 nuclei in a cell
111
double fertilization
a mechanism of fertilization in angiosperm in which two sperm cells unite with 2 cells in the female gametophyte (embryo sac) to form the zygote and endosperm
112
endosperm
result from double fertilization; triploid cell (3n)
a nutrient rich tissue formed by the union of a sperm with two polar nuclei during double fertilization; provides nourishment to the developing embryo in angiosperm seeds
113
monocot
has one cotyledon
endosperm is a liquid in these seeds (like coconuts and corn) with loose nuclei floating around that eventually cellularized into a starchy solid that provides nutrition to the embryo
114
eudicot
have two cotyledons (embryonic leaves)
endosperm starches are taken up by the growing embryo as the seed develops and is stored in the cotyledons
115
cotyledons
embryonic leaves
a seed leaf of an angiosperm embryo
116
pericarp
ovary wall becomes the thickened call of the fruit
117
growth
increase in size of a tissue
118
cell division
increasing cell number
119
cell elongation
increasing a cell size
120
determination
commitment of a cell to a particular fate
121
differentiation
the process of expressing the characteristics of a particular cell fate or tissue identity
122
shoot system
the aerial portion of a plant body consisting of stems, leaves, and flowers
123
shoot apical metistem
the tip of the shoot is the primary site of cell division for the shoot
124
root apical meristem
the tip of the root that is the primary site of cell division for the roots
125
apical meristem
a localized region at a growing tip of a plant body where one or more cells divide repreatedly
dividing cells enable plant to grow in length
126
coleoptile
the covering of the young shoot of the embryo of a grass seed
127
epicotyl
embryonic shoot above the cotyledons (tipped by SAM)
embryonic axis above the point of attachment of the cotyledons and below he first pair of miniature leaves
128
hypocotyl
embryonic shoot below the cotyledons
the embryonic axis below the point of attachment of the cotyledons and above the radicle
129
radicle
embryonic root of a plant (tipped by RAM)
130
apical hook
hypocotyl emerges bent in a hook that protects the SAM as shoot grows to soil surface
131
node
a point along the stem of a plant at which leaves are attached
sites where structures extend from stems
132
internode
spans of stem between nodes
a segment of a plant stem between the points where leaves are attached
133
branches
stems that develop from auxiliary buds that grow from axils
134
axillary bud
a structure that has the potential to form a lateral shoot or branch
appears in the angle formed between a lead and a stem
135
axil
intersections where leaf meets stem
136
blade
flat part of the leaf that’s intercepting light to do photosynthesis and then send that sugar to the rest of the plant
137
petiole
stem-like structure supporting the blade; connects blade of leaf to stem
the stalk of a leaf which joints the lead to a node of the stem
138
dermal tissue
covers and protects the plant from external insults (pathogens, predators, etc.)
help plants retain moisture the plant has within
the protective coating of plants
139
ground tissue
anything not dermal or vascular; can serves as the sites of photosynthesis, provide the supporting matrix for the vascular tissue, and help store water and sugars
140
vascular tissue
transport water, minerals, and sugars throughout the plant
plant tissues consisting of cells joined into tubes that transport water and nutrients throughout the plant body
141
parenchyma
type of ground tissue
alive at maturity
simple cell walls (made of cellulose and not particularly thick)
can perform diverse functions (photosynthesis, starch storage, water movement, may divide and differentiate into other cell types)
a relatively unspecialized plant cell type that carries out most of the metabolism, synthesizes and stores organic products, and develops into a more differentiated cell type
142
collenchyma
type of ground tissue
alive at maturity
more thickened cell walls, especially at the corners —> allows them to create more connected structures and often run parallel to the stem surface
function and provide structural support
colla = glue
a flexible plant cell type that occurs in stranded or cylinders that support young parts of the plant without restricting growth
143
sclerenchyma
type of ground tissue
scleros = hard
have lignin embedded in very thick cell walls
function in support and protection
often dead but may be alive (lignin prevents things from entering and exiting —> nutrients, water, etc.
a rigid supportive plant cell type usually lacking a protoplasm and possessing thick secondary walls strengthened by lignin at maturity
144
sclereids
type of sclerenchyma
several cells found in a cluster
formation of a harder surface
small with thick walls
often found in fruit walls like nut shells or in seed coats
145
fiber
type of sclerenchyma
cells are elongated and found in bunches
function in structural support
146
epidermis
the layer of tightly packed cells that form the outermost tissue of all plants
protect the plant from all environmental insults
leaf and stem are epidermal cells coated in cuticle that helps prevent desiccation
147
guard cells
type of epidermal cell
two cells that flank the stomatal pore and regulate the opening and closing of the pore
148
pavement cell
type of epidermal cells
cells that are very tightly packed together that create an outer skin of the plant
149
trichomes
hairlike outgrowths on stems, leaves, or flowers that come in diverse forms
an epidermal cell that is a highly specialized, often hairlike outgrowth on a plant shoot
can be glandular (able to manufacture and secrete chemicals) or nonglandular
function in defense from herbivores, thermoregulation, reflection, reducing evaporation, reaction triggers
150
root hair
increase surface areas for water absorption and minerals
a tiny extension of a root epidermal cell, growing just behind the root tip and increasing SA for absorption of water and minerals
151
xylem
vascular plant tissue that conducts water and minerals UPWARD from the roots to the rest of the plant
consist mainly of tubular dead cells
152
tracheid
a long, tapered water-conducting cell found n the xylem of nearly all vascular plants
functioning tracheids are dead
relatively, NARROW, dead when functional with totally open interiors and lignified cell walls
no openings at end; water moves laterally by pits where tracheotomy cells are in contact with
153
vessel element
open, dead cells with lignified cell walls, but much wider
open end to end allowing formation of long vessels with free water movement
a short, wide, water-conducting cell found in the xylem of the most angiosperm and a few non-flowering vascular plants
dead at maturity
154
phloem
vascular plant tissue consisting of living cells that transport sugars and other organic nutrients to the rest of the plant
cells arranged into elongated tubes
155
sieve tube elements
connect end to end allowing formation of sieve tubes
a living cell that conducts sugars and other organic nutrients in the phloem of angiosperms
end are not totally open
156
sieve plates
end walls present but with many pores
an end wall in a sieve tube element which facilitates the flow of phloem sap in angiosperm sieve tubes
157
companion cell
paired, non-conducting cells are connected to sieve tube elements
a type of plant cell that is connected to a sieve tube element by many plasmodesmata and whose nucleus and ribosomes may serve one or more adjacent sieve tube elements
158
plasmodesmata
channels that pass sugars, nutrients, and large molecules necessary to keep sieve tube elements alive to them
an open channel thru the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some larger molecules to pass between the cells
159
taproot
the main vertical root that develops from an embryonic root and gives rise to lateral (branch) roots
160
lateral root
secondary branches
a root that arises from the pericycle of an established root
161
fibrous root
primary root die and instead a shallow network establishes with new roots that come off the stem and where no one branch predominates
162
root cap
terminal structure that first encounters obstacles
protects the RAM
secretes a slime that allows growth thru soil
site of gravity perception
a cone of cells at the top of a plant root that protects the apical meristem
163
zone of differentiation
area where cells takes on their distinct types (e.g. root hairs emerge)
region of root with the oldest root cells
164
zone of elongation
cells can grown up to 10x initial length, pushing tip down further into soil
165
zone of cell division
includes RAM and its immediate products of cell division
166
cortex
starch tissue storing parenchyma with intercellular spaces
ground tissue that is between the vascular tissue and dermal tissue in a root or eudicot stem
167
endodermis
one cell thick layer that creates a boundary with the vasculature
the innermost later of the cortex that surrounds the vascular cylinder
168
pericycle
outer vascular layer surrounding the xylem and phloem
lateral roots arise from meristematically active regions
169
macronutrients
an essential element that an organism must obtain in relatively large amounts
c, h, o = fixed as sugars by photosynthesis (h2o + co2)
p, k, n, s, ca, mg = come from soil (1-4% dry weight)
170
micronutrient
an essential element that an organism needs in very small amounts mostly as enzymatic co-factors
too much = bad
cl, cu, fe, mn, zn, mo, b, ni
171
symplast
all the cytosol contained within plasma membranes
the continuum of cytosol connected by plasmodesmata between cells
plasmodesmata pass thru plasma membranes and cell walls
172
apoplast
everything exterior to cell membranes
water, minerals, and other dissolved substances can move thru cell walls, intercellular spaces of cortex, and space between dead structures (xylem vessels, tracheids)
173
transmembrane route/plasma membrane
a filter —> selectively permeable
substances pass thru the routes while still in the cortex via the plasma membrane
174
plasma membrane
the membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition
175
casparian strip
a layer of waxy and waterproof material (suberin) that blocks all passage
a water impermeable ring of wax in the endodermal cells of plants that blocks the passive flow of water and solutes into the stele by the way of cell walls
176
suberin
layer of waxy material on the casparian strip
177
phyllotaxy
the non-random order and arrangement of primordia initiation
178
simple leaf
has a single, undivided blade
179
compound leaf
the blade consists of multiple leaflets
leaflet has no axillary bud at its base
180
rhizomes
underground stems that can put up new shoots
181
stolons
“runners”
stems that extend along the soil surface and establish new plantlets with leafs and roots at nodes
persist even if cut or original plant dies
182
stem tubers
enlarged ends of rhizomes or stolons that store food
183
thorns
modified axillary branches
modified for defense
184
prickles
NOT MODIFIED AXILLARY BRANCHES
modified epidermal extensions of the stem
185
secondary growth
drives the thickening of plant stems
growth produced by lateral meristems, thickening the roots and shoots of woody plants
mostly occur in eudicots and conifers
involves new lateral meristems self-renewing tissues that form cylindrical bands (or circular band in cross sections) once that part of the stem has finished elongating/primary growth
186
primary growth
growth produced by apical meristems, lengthening / elongating stems and roots
187
vascular cambium
lateral meristematic tissue that runs between xylem and phloem
adds more of those tissues, widening the shoot while also increasing vascular flow and support
a cylinder of meristematic tissue in woody plants that adds layers of secondary vascular tissue (secondary xylem/ wood and secondary phloem)
188
cork cambium
lateral meristematic tissue that develops from parenchyma within the cortex
produces a tough, thick, waxy covering (cork) that protects stem from water loss and from invasions by pathogens and insects
a cylinder of meristematic tissue in woody plants that replaces the epidermis with thicker, tougher, cork cell
189
cork
tough, thick, waxy covering that protects stems from water loss and from invasions by pathogens and insects
190
secondary xylem
cells are formed in the INSIDE of the VC
become wood
191
secondary phloem
cells form to the OUTSIDE of the VC
become bark
192
annual rings
inner xylem tissue grows unevenly across seasons
193
sapwood
most recent several layers of secondary xylem which DO conduct water
194
heartwood
older layers of secondary xylem which NO LONGER conduct water
195
cohesion
linking of like molecules often by hydrogen bonding
196
surface tension
consequence of cohesion
measure of how much force is needed to break the water surface
197
evaporation
water becomes water vapor —> energy required to break h-bonds
198
transpiration
loss of water vapor from leaves
199
osmosis
PASSIVE diffusion of water down the concentration gradient across a membrane
diffusion of free water across a selectively permeable membrane
200
bulk flow
movement of fluid due to a difference in pressure between two locations
201
active transport
pumps ions across a membrane to create a concentration gradient
movement of a substance across a cell membrane against its concentration or electrochemical gradient, mediated by specific transport proteins and requiring an expenditure of energy
202
water potential (psi)
the physical property that predicts which direction water will move
governed by solute concentrations and applied pressure
203
turgid
swollen or distended
a walled cell becomes turgid if it has a lower water potential than its surroundings, resulting in the entry of water
when placed in an environment with high conc of free water, water will rush into the cell
204
turgor pressure
force directed against a plant cell wall after the influx of water and swelling of the cell due to osmosis
positive pressure potential
205
solute potential (psi, s)
component of water potential that is proportional to the molarity of a solution
measures the effect of solutes on the direction of water movement
either 0 or negative
always negative when solutes are present
206
pressure potential (psi, p)
a component of water potential that consists of the physical pressure on a solution, which can be positive, 0 or negative
207
mesophyll
middle + leaf
between top (bundle sheath cells) and bottom epidermis
208
palisade mesophyll
consists of elongated chloroplast rich cells specialized for light capture
209
spongy mesophyll
form a porous space with high SA:V ratio that allows for gas circulation
210
bundle sheath cells
surround veins and regulate transfer of substances between mesophyll and vasculature
211
phloem sap
the sugar rich solution carried thru a plant’s sieve tubes
212
phenotypic plasticity
phenotypic variation produced due to individuals of the same genotype experiencing different environments
capacity of an individual genotype to produce different phenotypes to change its traits depending on the environment experience
213
developmental plasticity
environment dependent changes in growth, developmental patterning, or developmental timing
often an environmental cue experienced by one tissue or life stage determines the developmental response by another tissue or life stage
214
perception
sensing and interpreting complex environmental cues
215
transduction
communication information (the cues) to nucleus OR to another tissue entirely
216
response
local changes to cells and tissues appropriate to the stimuli perceived
217
cue
stimulus from the environment (biotic or abiotic)
218
sensor
some type of protein, hormone, etc. that
a receptor of the cue that responds to the stimulus
219
hormone
mobile signal that acts to alter development or function of a target tissue
in multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body parts of the organism, changing the target cells’ functioning
220
tropism
growth response that results in plant organs turning toward or away from stimuli due to differential rates of cell elongation
221
phototropism
growth in response to a direction light source
bend toward light source
222
auxin
a term that primarily refers to indoleacetic acid (IAA), natural plant hormone that has a variety of effects, including cell elongation, root formation, secondary growth, and fruit growth
drives asymmetric growth in coleoptiles in response to light
223
phototropins
blue light receptors
224
expansins
plant enzyme that breaks the crosslinks (h-bonds) between cellulose microfibrils and other cell wall constituents, loosening the wall’s fabric
225
PINs
transporters of auxin localized to the cell membrane
requires active transport
226
gravitropism
directional growth in response to the force of gravity
227
statoliths
starch granules that sense gravity and settle to the lowest side of cells
a specialized plastid that contains dense starch grains; may play a role in detecting gravity
228
thigmotropism
a directional growth of a plant in response to touch
229
hydrotropism
directional growth in a plant in response to water
roots will grow toward a a water source
230
heliotropism
a symmetrical growth of the stem over the course of the day to follow the relative position of the sun int he sky and then at night reorient back to face at the anticipation of dawn
231
dormancy
state of slow metabolism and suspended of growth and development
a condition typified by extremely low metabolic rate and a suspension of growth and development
232
abscisic acid (ABA)
hormone that generally slows growth
a plant hormone that slows growth, often antagonizing the actions of growth hormones; two of its many effects are to promote seed dormancy and facilitate drought tolerance
233
gibberellins (GAs)
hormone that promotes both cell division and elongation
any of a class of related plant for one’s that stimulate growth in the stem and leaves, trigger the germination of seeds and breaking of bud dormancy and (with auxin) stimulate fruit development
234
phytochrome
sensors of red and far-red light
plant pigments that absorb mostly red and far-red light and regulate many plant responses, such as seed germination and shade avoidance
235
red:far-red ratio
indicates shade and what light the leaves have absorbed photosynthetically
236
shade avoidance
in plants that have a high RFR, they grow shorter than a low RFR
plants crowded out = need to compete
need to grow taller, flower earlier
low R:FR ratio —> more in Pr form
237
karrikins
specific activating signals in smoke
plant growth regulators in smoke form burning plant material
238
inflorescence meristem
putting our determinate floral meristems/primordia where it was making leaves
what the SAM becomes
239
floral meristem/primordia
inflorescence meristem becomes fully determinate
produce the structures present in a flower —> no more self renewing cells
self renewing cells have come to a determined fate
240
circadian rhythms/clocks
a physiological cycle of about 24 hours that persists even in the absence of external cues
241
long-day plants
flowering occurs earlier or only when day length is above a minimum threshold
242
short-day plants
flowering occurs earlier or only when day length is below a maximum threshold
243
day neutral plant
grows in any amount of sun light during the day; doesn’t care
244
facultative
capable/promotive of a function but not restricted to a particular function or mode of life
245
obligate
threshold must be passed in order to grow
246
florigen
a flowering signal in both LD and SD plants
made in leaves under certain conditions and that travels to the SAM inducing them to switch from vegetative to reproductive growth
247
external coincidence
florigen gene expression is dependent on the upstream genes that of FT that promote or repress its expression but its regulated by the circadian clock and only function when expressed coincident with light
248
vernalization
promotion of competency to flower by prolonged exposure to cold
249
juvenile to adult phase transition
juvenile plants aren’t competent to respond to environmental signals that promote flowering; long juvenile phases are a common obstacle to breeding and production of tree crops
250
ethylene
a gaseous plant hormone important to ripening fruit and abscission
a gaseous plant hormone involved in responses to mechanical stress, programmed cell death, leaf abscission, and fruit ripening
251
ripening
process by which a tart, hard, green fleshy fruit becomes sweet and soft to attract animals for dispersal
252
abscission
detachment at a defined zone
253
rhizobium
nitrogen fixing bacteria associated with legumes
plant supplies nutrients to the rood nodules and withdraws nitrogen rich compounds from the nodules
254
striga
witchweed
parasitic plant that ravages over 100 million hectares of cereal and legumes crops annually, causing severe losses throughout Africa and parts of Asia
255
strigolactones
any of a class of plant hormones that inhibit shoot branching, trigger the germination of parasitic plant seeds and stimulate the association of plant roots with mycorrhizal fungi
256
PAMP triggered immunity (PTI)
recognize molecules that are very diagnostic of microbes or fungi
the first layer of plant immunity that restricts pathogen proliferation
257
effector
a pathogen encoded protein that cripples the host’s innate immune system
block the immune signal and response
258
NLRs (nucleotide binding/leucine-rich-repeat proteins)
recognize effectors or plant proteins that have been altered by effectors
act to elicit immune responses including means of sub cellular resistance and cell-death
259
hypersensitive response
programmed cell death of infected cells and their neighbors
production of antimicrobial molecules, adding more lignin cell to seal off infection, destruction of cell contents
prevents pathogen spread by depriving it of nutrients
260
system acquired resistance
methylsalicylic acid to salicylic acid induces this
state of elevated resistance to infection not just by the triggering pathogen by all pathogens
261
methylsalicylic acid
infect cells release this into the phloem which moves thru the plant to tell the plant there’s pathogens around
