Exam 3(pre-ME3) Flashcards
1
Q
What adaptations have pathogens started using for success?
A
Pain, lethargy, necrosis
2
Q
Virulence
A
spectrum of bacterial harmfulness, avirulent=not harmful
3
Q
Factors
A
bacterial genes that can cause harm, often proteins, depends on microbe’s genome and proteome
4
Q
what type of gene transfer is conjugation?
A
horizontal gene transfer
5
Q
Purpose of virulence factors
A
gain access to nutrients from host
6
Q
Purpose of biofilms
A
help organisms stay in one place
7
Q
Strategy of pathogens in hosts
A
adhesion, invasion, colonization/growth, tissue damage/disease
8
Q
what strategies of pathogens in hosts don’t always occur?
A
invasion and tissue damage/disease
9
Q
Ice nucleation
A
some bacteria can produce proteins(INPs) that serve as ice nucleators, they form ice crystals at lower temps, water freezes around the protein at warmer temps
10
Q
Proteases, lipases, nulceases
A
break down lipids, proteins and nucleic
11
Q
Collagenase
A
breaks down collagen, gas gangrene
12
Q
Clostridium
A
genus that is endospore producing, anaerobic organisms
13
Q
Streptokinase
A
causes strep throat, scarlet fever and necrotizing fasciitis, dissolves fibrin
14
Q
fibrin
A
a connective tissue, forming a large cable to holding things together
15
Q
post-debridement
A
removal of dead tissue
16
Q
Coagulase
A
causes blood to clot, white blood cells struggle to get to bacteria to fight them
17
Q
What do staph infections do?
A
they cause blood to clot with cuagulase
18
Q
endotoxins+examples
A
not actively secreted, general symptoms, LPS of gram negative bacteria, part of outer gram negative membrane, less toxic than exotoxins
19
Q
Exotoxins+examples
A
secreted, very specific targets, A-B, cytolytic, super antigen, botulinum, tetanus, more toxic than endotoxins
20
Q
What affect does LPS have on the immune system?
A
Sepsis or septic shock
21
Q
What do large doses of endotoxin cause?
A
Hemorrhagic shock, tissue necrosis
22
Q
Botulinum toxin
A
exotoxin, produced by clostridium botulinum, most acutely lethal toxin known, obligate anaerobe, antibiotics often can’t help, come from improperly preserved foods and spores in honey, block acetylcholine(AC) that causes muscle to contract, often causes death from not being able to breathe, tiny amounts used in botox
23
Q
Tetanus toxin
A
produced by clostridium tetani, obligate anaerobe, come from puncture wounds, released from site of growth
24
Q
Why are deep tissues beneficial to some bacteria?
A
they are anaerobic environments where endospores can germinate
25
Toxoid
used to teach the immune system how to recognize the toxins
26
Plant morphology+examples
studies external physical form and structure of the parts/organs of plants paying attention to their evolutionary origin , examples include flowers and thorns
27
Flowers
"modified" or evolved leaves
28
Thorns
stems that have the position and internal structure of stems
29
Plant anatomy+examples
studies internal structure of plants at the sub-organ level, aimed at understanding tissues and cells as the relate to organ function, examples include xylem and phloem tissue and photosynthetic tissue
30
Roots
anchor plant, absorb minerals and water, store carbs
31
stems
shoot system, produce leaves and branches, bear the reproductive structures
32
Leaves
shoot system, flattened structures specialized for photosynthesis
33
Where do all parts of a plant that aren't roots, stems and leaves come from?
they are all modified roots, stems and leaves
34
Taproot
1 large vertical root with many small lateral or branch roots, dicots
35
Fibrous roots
mat of slender roots spreading out, monocots
36
Root hairs
increase absorptive surface area
37
Prop roots
propped above the ground
38
Pneumatophores
Stick out of the ground/water
39
Strangling aerial roots
wrap around a structure before going into the ground
40
Buttess roots
large, wide roots
41
Foods that are examples of modified roots
Carrots, sugar beets, radishes and sweet potatoes
42
Nodes
points at which leaves are attachedq
43
antinodes
stem segments between nodes
44
buds
growth of shoot
45
apical bud
tip of the plant
46
axillary bud
in nodes on stem
47
Food this is an example of a modified stem
potatotes
48
Modified stems that perform alternative functions
rhizomes, stolons, fibers
49
function of leaves
photosynthesis, gas exchange, dissipate heat, defend plant from herbivores and pathogens
50
simple leaves
"entire" margin, continuous all the way around the leaf without touching the central midrib
51
compound leaf
leaves that have margins that touch the central midrib, each lobe forms a leaflet
52
reproductive leaves
have plantlet, line stem
53
storage leaves
inner part of onion, don't line stem
54
thorns
sharp, pointed, modified stem
55
Spines
sharp, pointed, modified leaf/stipule
56
Prickle
sharp outgrowth from epidermis or bark
57
Plant tissues
all organs, roots, stems, leaves and their modified versions are composed of different types of tissues
58
Dermal tissue
plant tissue, "skin" of plant, single layer of tightly packed cells that cover and protect the plant
59
Vascular tissue
plant tissue, transport materials between roots and shoots, xylem and phloem
60
Ground tissue
plant tissue, any type of tissue other than dermal or vascular tissue. Includes storage and photosynthetic tissue. Bulk of plant tissue
61
Parenchyma
plant cell type, thin primary cell walls, least specialized, photosynthetic cells, storage cells, parents of other cells
62
Collenchyma
plant cell type, thick primary walls, support young parts of the plant shoot, alive at maturity, in phloem
63
Sclerenchyma
very thick, wood, contain lignin, specialized just for support and strengthening, dead at functions maturity, xylem vessels, seed coats
64
Xylem
transport water and minerals up the roots to leaves and other parts, tube shaped dead cells, tracheas and vessel elements, less complicated than phloem
65
Phloem
transport sugars and other organic molecules generally down from leaves to other parts of the plant, tube shaped living cells, sieve tube elements and companion cells, more complicated than xylem
66
Monocot
one cotyledon, mostly parallel veins, vascular tissue is scattered, root system is usually fibrous(no main root), pollen grain has one opening, floral organ in multiple of 3, parenchyma in center of root
67
dicot
2 cotyledons, mostly netlike veins, vascular tissue in a ring, taproot present, pollen grain has 3 openings, floral organs in multiples of 4 or 5, xylem and phloem in center of root,
68
annual plants+examples
complete life cycle in a year or less, sequence is germination then flowering the seed production, examples are some flowers, corn, soybean, wheat and rice
69
perennials+examples
lives for many years, don't die of old age, only disease or trauma. Examples include trees, shrubs and some grasses
70
Meristems
regions of cell division where plants produce new tissues and organ through mitosis, region of undifferentiated cells, like embryonic tissue, regenerates new cells
71
Apical meristem
primary meristem, grow in length, primary growth, 2 types: shoot and root
72
Primary growth
Growth in length of shoots and roots
73
lateral meristems
secondary meristems, growth in girth, secondary growth
74
secondary growth
growth in thickness of shoots and roots, produced by secondary meristems
75
protoderm
type of dermal tissue, surround meristem, outer layer
76
pro cambium
type of vascular tissue , middle of meristem
77
ground meristem
type of ground tissue, surround pro cambium
78
root cap
protects meristem, secretes polysaccharide slime that helps penetrate soil
79
herbaceous plants
die each year
80
Woody plants
grow each year, evolved from dying each year, grow in height from tip and diameter from sides(secondary growth) for strength, phloem produced on outside, xylem produced on inside, dicot
81
vascular cambium
makes xylem and phloem, growing ring around tree, comes from secondary growth
82
cork cambium
makes bark, growing ring around tree, comes from secondary growth
83
vegetative growth
produces all parts of a plant such as roots, stems, and leaves but no flowers, fruits or seeds
84
reproductive growth
produces flowers and their product including fruits and seeds
85
hormones
coordinate growth, development, and responses to stimuli. They are signaling molecules produced in low concentrations by one part of the body and it is transported elsewhere. It binds to a specific receptor and triggers responses in target cells/tisses
86
What is special about plant hormones?
they can also have significant effects in the same cells where they are synthesized
87
Plant growth regulators
glucose and synethic/artificial plant hormones
88
Where is auxin produced?
Shoot apical meristems and young leaves primarily. Also produced in root apical meristems, root still depends on shoot for most auxin.
89
Auxin functions
(IAA)stimulate stem elongation in low concentrations, promotes formation of lateral and adventitious roots, regulates fruit development, enhances apical dominance, function phototropism and gravitropism, promotes vascular differentiation, retards leaf abscission
90
Where is cytokinin produced?
primarily synthesized in roots and transported elsewhere, other minor sites of production
91
Cytokinin function
regulate cell division in shoots and roots, modify apical dominance, promote lateral bud growth, promote movement of nutrients into sink tissues, stimulate seed germination, delay leaf senescence
92
Where are gibberellins produced?
meristems of apicals buds/roots, young leaves and developing seeds
93
gibberellins functions
stem elongation, pollen development, pollen tube growth, fruit growth, seed development and germination, sex determination, transition from juvenile to adult phases
94
Where is abscisic acid produced?
almost all plant cells can produced abscisic acid, it is present in every major organ and tissue, transported in xylem and phloem
95
Abscisic acid function
(ABA)inhibits growth, promotes stomatal closure during drought stress, promotes seed dormancy and inhibits early germination, promotes leaf senescence, promote desiccation tolerance
96
Where is ethylene produced?
Gaseous hormone produced in most of the plant, produced in high concentrations during scenesence, leaf abscission and the ripening of some fruits. Also stimulated when there is a wound or stress
97
Functions of ethylene
promotes ripening of fruit, leaf abscission, and triple response in seedlings(inhibition of stem elongation, promotion of lateral expansion, and horizontal growth); enhances rate of senescence, promotes root and root hair formation, promotes flowering in the pineapple family
98
Where are brassinosteroids produced?
Present in all plant tissues, different intermediates in different organs, produced near sites of synthesis
99
functions of brassinosteroids
Promote cell expansion and cell division in roots, promote root growth at low concentrations, inhibit root growth at high concentrations, promote xylem differentiation and inhibit phloem differentiation, promote seed germination and pollen tube elongation
100
where are jasmonates produced?
produced in several parts of the plant and travel in the phloem to other parts of the plant
101
functions of jasmonates
regulate many functions, small group of related molecules derived from the fatty acid called linolenic acid, regulate fruit ripening, floral development, pollen production, tendril coiling, root growth, seed germination, and nectar secretion. produced in response to herbivory and pathogen invasion
102
Where are strigolactones produced?
produced in roots
103
functions of strigolactones
carotenoid derived hormones and extracellular signals the respond to low phosphate conditions or high auxin flow from shoot. They promote seed germination, control apical dominance, and attraction mycorrhizal fungi to the root
104
tropism
growth toward or away from any stimuli
105
thigmotropism
tropism in terms of touch
106
Discovery of auxins/phototropism
Charles and Francis Darwin were the first to publish phototropism experiments. Shoots seedlings that were left uncovered in their experiment grew towards light and covered/removed seedling shoo tips did not respond too light. Seedlings influenced lower shoot portions
107
What is true of the tip of a stem in phototropism?
phototropism occurs when the tip is separated by a permeable barrier but not an impermeable barrier
108
How does auxin work in phototropism?
Auxin is more highly concentration on the dark side of the plant and that part of the plant grows/elongates more
109
Gravitropism
controlled by auxin, plant grows away from gravity
110
polar auxin transport
transport of occurring from root to shoot
111
how does auxin increase cell elongation?
loosening cellulose microfibrils and other cell wall parts. it increases activity of proton pumps, low pH activates expansions, and polysaccharides are cleaved by cell wall loosening enzymes, loosening the microfibrils
112
How are synthetic toxins used?
Eudicots experience a hormonal overdose and die, while monocots can inactive them
113
How does 2-4, D cause defoliation?
application of this synthetic auxin causes plant to synthesize ethlyene, forming the abscission layer in petioles and leaves fall off the plant
114
Apical dominance
terminal bud's ability to suppress development of axillary buds, under control of sugar, cytokinins, auxins, and strigolactone
115
What would removal of apical bud result in?
Increase in sugar availability and decrease in auxin and strigolactone levels, initiating axillary bud growth. Topmost axillary bud grows and takes over, splits into 2
116
Bolting
internodes grow long and the plant flowers, cabbage can be bolted by applications of Ga3
117
gibberellin role in seed germination
water is imbibed, gibberellins are released from embryo to signal germination
118
ein
mutation in which plants fail to undergo the triple response after exposure to ethlyene
119
ctr
constitutive triple-response mutants undergo a triple response even if ethylene is not present
120
What are most events in plants involved with+examples
pre-programmed cell death, examples include death of annual plant after flowering, differentiation of xylem vessels, loss of cytosol and shedding of autumn leaves
121
purpose of unripened fruits
hard, tart fruit protects developing seed from herbivores
122
Ripened fruits
sweet, soft fruit that attracts animals to disperse seed, cell wall softens/breaks down, conversion of starch to sugar sweetens fruit
123
positive feedback system with ethylene
ethylene triggers ripening, ripening stimulates more ethylene production
124
How does ripening affect other fruits?
Ripening apple releases ethylene to speed ripening of nearby fruits
125
How does CO2 affect ripening?
inhibits synthesis of new ethylene
126
What is the stress response caused by ABA
stomatal closure during drought, K channels in plasma membrane of guard cells to open leading to potassium loss, loss of water closes stomatal pores
127
how do animals and plants respond to stimuli?
Animals: change behavior, more toward positive stimuli and away from negative stimuli
Plants: adjust growth and development
128
what stimuli do plants respond to?
light, day/night length, season, gravity, stress, abiotic(drought/flooding/etc.) and biotic(pathogens and herbivores)
129
signal transduction pathway
reception, tranduction and repsonse
130
transduction
receptor triggers internal secondary messengers, bridge between reception and response
131
photomorphogenesis
the effect of light on plant growth, only a small amount of light energy drive changes in growth and development
132
Chemical event in photosynthesis
strong light energy drives reduction of CO2 to carbohydrate
133
de-etiolation
growing stem changes from white with no leaves or roots to green with leaves and roots
134
photoreceptors
pigments, usually proteins, with an attached light-absorbing chromophore.
135
Blue-light receptors
Play a role in phototropism that is mediated by auxin. stomatal opening and closing and chloroplast movements
136
Red-light receptors
phytochromes, de-etilation, seed germination, shade avoidance, photoperiodism and flowering
137
etiolated plants
longer, spingly, not green, from growing in the dark
138
Pr
absorbs right light
139
Pfr
absorbs far red light
140
phytochrome response to light
etiolation and de-etiolation
141
phytochrome role in seed germination
switches between two forms and affects germination of lettuce seeds and many other responses
142
Response to Pr
slow conversion to darknes in some species
143
Response to Pfr
Enzymatic destruction, seed germination, inhibition of vertical growth and stimulation of branching, setting internal clocks and control of flowering
144
how do red and far red light affect seed germination?
red light stimulates and far red inhibits germination. the last light that seeds are exposed to is most important
145
photoperiodism
physiological response to photoperiod, influences timing of flowering and dormancy
146
photoperiod
relative lengths of night and day
147
Factor that determines flowering in plants
night length
148
how is flowering in plants classified?
long-day, short day or neutral day
149
how do plants measure night length?
by how much Pfr remains at the end of the night. long night result is lower Pfr concentrations at dawn
150
long day vs short day vs day neutral plants
long day: flower when night is shorter than a certain length, usually in early spring/summer
Short day: flower when night is longer than a certain number of hours, usually late summer or early fall
day-neutral: flower regardless of night length as long as day length meets minimal requirements for plant growth
151
Florigen
transmissible, flowering hormone
152
plant response to drought
Produce ABA, reduce water loss by closing stomata
153
Plant response to flooding
formation of air tubes that help roots survive oxygen deprivation
154
Plant responses to salt
avoid osmotic water loss by producing solutes tolerated at higher concentrations
155
Plant response to heat
synthesis of heat-shock proteins that reduce protein denaturation at high temps
156
Plant response to cold
adjust membrane fluidity, avoid osmotic water loss, produce antifreeze proteins
157
Physical response to biotic plant enemies
thorns, spines, prickles and trichromes
158
hypersensitive response
plant response in which local cell and tissue death at and near the infection site to restrict the spread of a pathogen
159
systematic acquired resistance
a generalized defense response in organs distant from the infect site
160
effectors
protein generated by a pathogen that infects a plant
161
plant hormones used in immune defense
Salicylic acid(SA), Jasmonic acid(JA) and Ethylene(ET)
162
plant response to caterpillars/herbivores
wounding from an animal eating the plant and the chemical in the herbivore saliva trigger a signal transduction pathway that causes the release of volatile attractants for predators of that herbivore
163
How do humans help plants against pathogens?
breed resistant species with resistant genes
164
how are most solutes moved into plant cells
active transport
165
apoplastic route
move through connectd cell wall without crossing cell membrane, fastest route but does not result in cell entry
166
symplastic route
move from cell to cell through cytosol
167
transmembrane route
repeated crossing ofplasma membranes, slowest but offers more control and is the safest route
168
why can't water use the apoplastic route all the way from the root hair to the xylem?
it must cross the endodermis through the symplastic route
169
stele
vascular cylinder within endodermis
170
casparian strip
belt made of suberin, waxy material that is impervious to water and dissolved minerals, forces fluid through selective cell membrane and into symplast
171
methods of loading sucrose into the phloem
1. sucrose manufactured in mesophyll cells can travel via the symplast to sieve-tube elements
2. chemiosmotic mechanism is responsible for the active transport of sucrose
172
bulk flow
movement of fluid driven by pressure
173
pulling force in xylem
negative pressure pulling upwards, created evaporation of water at the leaf surface creating a suction effect
174
water drives the direction of water movement?
water and dissolved nutrients from root to leaves along a gradient of water potential that is highest in the root and lowest in the leaf
175
pushing force in phloem
positive pressure pushing sugar from leaves through the sieve tube to sinks(hydrostatic pressure)
176
sinks
parts of the plant receiving organic molecules from the leaves
177
When can the phloem contents move upwards?
in the winter
178
macro and micro nutriens
macronutrients: required in larger amounts
micronutrients: required in smaller amounts, primarily cofactors
179
macronutrients needed for synthesis and their sources
1. C from CO2
2. O from CO2
3. H from H2O
180
macronutrients from soil and fertilizer and their functions
1. N: protein and nucleic acid synthesis
2. P: nucleic acid, ATP, phospholipids
3. K: stomata control, water balance
181
Macronutrients from the soil and their functions
1. Ca: cell wall and membrane structure, regulation
2. Mg: chlorphyll
3. S: proteins and enzymes
182
how do roots uptake cations?
active transport, aided by secretion of H+ by root cells(proton pump) that acidifies the soil solution. CO2 reacts with H2O
183
N deficiency
shown first by older leaves because N is mobile-can be removed from older leaves and transported to younger leaves, yellowing of leaves
184
Fe deficiency
shown first in younger leaves because Fe is not mobile, it cant be removed from older leaves , yellowing of leaves
185
how do plants get N
they take up Nitrate produced by bacteria in the soil
186
Symbiotic relationship between soybean root nodules and Rhizobium
1. plants release signals to attract bacteria, infection thread forms
2. bacteroids form
3. growth continues and a root nodule forms
4, nodule develops vascular tissue
5. mature nodule grows to be many times the diameter of the root
Mutualistic relationship
