plant bio exam 3 Flashcards
(201 cards)
1
Q
organs of plant body
A
roots
stems leaves
2
Q
tissues of plants
A
ground
vascular
dermal
3
Q
ground tissue system
A
largest system, most of plant body
ex: pith, cortex, mesophyll
4
Q
vascular tissue system
A
distribution of fluids and solutes
ex: xylem, phloem
5
Q
dermal tissue system
A
protection and covering
ex: epidermis, periderm
6
Q
simple tissue
A
composed of one type of cell
ex: parenchyma tissue
7
Q
complex tissues
A
composed of multiple cell types
ex: xylem
8
Q
parenchyma cells
A
ground tissue
many shapes, often elongated/spherical
found in all organs
lignified cell wall
living at maturity
mature parenchyma cells can differentiate into other cell types
9
Q
lignin
A
rigid, supportive polymer that prevents water entry except through special openings
10
Q
collenchyma cells
A
ground tissue
elongated specialized for support
living at maturity
walls composed of alternating cellulose and pectin
thickened corners allow flexibility and growth
often found on outer edges of cortex, near epidermis
11
Q
collenchyma tissue
A
aggregated collenchyma provide support to stems
tissue can form cylinders or strands
ex: ridges on celery stalk
12
Q
sclerenchyma cells
A
ground tissue
rigid for support and structure
lignified cell walls
dead at maturity
fibers: long, narrow, sometimes flexible
sclereids: hard, rigid cells with thicker cell walls than fibers
13
Q
sclerenchyma tissue
A
fibers: aggregate into long cable like structures or tubes around stems
sclereids: can occur in clusters (pear stone cells), sheets (seed coats), or individually
processed fibers can be made into rope, therads, textiles
14
Q
cells in ground tissue
A
parenchyma
collenchyma
sclerenchyma
15
Q
vascular tissue cells
A
tracheids and vessel elements
16
Q
xylem
A
complex tissue
water transport: vessel members, tracheids
support: fibers
loading: parenchyma (only living cells)
vascular bundles in young plants, vascular cylinder with growth
17
Q
tracheary elements
A
secondary cell walls spiral, annular, pitted, laddered, or netlike
annular and spiral wall: stretch to accommate growth in young plants
water is exchanged through pits
simple pits: occur in lignified parenchyma, fibers
bordered pit: secondary wall extends over pit chamber, occur in tracheids, vessel members, some fibers
18
Q
vessel
A
series of vessel members connected end to end
ends of cells for perforation plates
end cell of a vessel will have a closed end wall with bordered pits
members laterally and end to end via bordered pits
19
Q
tracheids
A
elongated, pointed ends
lack perforation plates
joined at ends via overlapping bordered pits
gymnosperms only have tracheids, no vessel members
both cell types have advantages and disadvantages
20
Q
phloem
A
nutrient transport
complex tissue: fibers, parenchyma, sieve tube
primary and secondary
sieve tubes
21
Q
primary phloem
A
in vascular bundles in young stems and roots
22
Q
secondary phloem
A
outside xylem in longer lived plants
23
Q
sieve tubes
A
conducting elements that transport sugar from leaves, formed from sieve tube members connected end to end
24
Q
sieve tube parts
A
central part of cell becomes full of p-protein
companion cells
sieve areas
sieve plate
gymnosperms have sieve cells with no sieve plated at their ends
25
companion cells
connect to sieve tube member
regulate metabolism
loading and unloading
26
sieve areas
clusters of pores in sieve tube member walls
27
sieve plate
sections of sieve areas on ends of sieve tube members
28
dermal tissue cells
epidermal cells
stomata
trichomes
29
epidermis
outer covering of plant
protection, gas exchange, photosynthesis, defense
epidermal cells, guard cells, trichomes
epidermal cells: elongated, alive at maturity, irregular walls
outer walls covered with cutin
30
stoma
pore for gas exchange surrounded by two guard cells
31
subsidiary cell
assists with opening and closing of stomata
32
guard cells and stomata
stoma
subsidiary cell
many stomatal adaptations and processes for optimum growth and moisture conservation
33
trichomes
hairlike epidermal growths
occur on multiple organs: root hairs, leaf trichomes
many shapes
can be galndular or not
34
periderm
protective layer on older stems/roots
phellum
cork cambium/phellogen
phelloderm
35
phellem
in periderm
outer cork cells with waxy suberin cell walls
dead at maturity
36
cork cambium/phellogen
in periderm
layer of dividing cork cells
37
phelloderm
in periderm
inner layer of longer-lived, parenchyma-like cells
38
meristems
sites of cell division and differentiation
sources of cells and tissues
apical meristem: growth at tip
primary meristem: growth upward
secondary meristem: growth outard
39
apical dominance
tendency of plants to grow upward at the apex (tip)
why carvings on trees stay at same level
40
primary meristems
elongate root and shoot tips
form primary tissues
protoderm: dermal tissues
procambium: primary xylem and phloem
grounde meristem: cortex and pith
41
secondary meristems
lateral growth
allows plants to grow thicker, increase circumference
not all species/organs have secondary growth
vascular cambium: develops secondary xylem and phloem
cork cambium: develops periderm
42
3 functions of roots
anchoring and supporting plants
absorbing water and nutrients
conducting material into plant body
43
rhizosphere
point of contact between roots and soil
thin zone (few mm), chemically complex
rich in microbes (bacteria, fungi)
44
root systems
2 kinds: fibrous, taproots
different anatomy, developmental pathways
characteristics of different plant groups and growth forms
45
taproots
single main root
branches develop from main axis
advantageous for reaching water deep in soil
common in desert plants
can be modified for storage
ex: carrot
46
fibrous roots
many main roots, heavily branched
no central axis
annuals may grow large fibrous root systems in one season
typical of monocots
47
adventitious roots
roots that arise from stem or leaf tissue
allow plants to propogate vegetatively and spead within habitats
many application in horticultures: cuttings, layering
48
prop roots
support plant stem or branches
arising from stems = adventitious
ex: corn, banyan`
49
pneumatophores
adventitious roots allow gas exchange
common in aquatic habitats
ex: bald cypress, mangrove
50
root tip: root cap
protects root apical meristem
site of gravity perception by roots
root cap cells slough off root tip, can persist and live in rhizosphere
51
root tip: root apical meristem
includes a quiscent center: site of very slow cell division, possible function for hormones
cells also divide to form root cap
forms 3 meristems: protoderm, ground meristem, procambium
52
region of elongation
immediately basal to root apical mersitem
division stops, elongation and differentiation begins
cells not yet mature
53
region of maturation
site of maturation of differentiated cell types
site of root hair formation
location varies: sometimes close to root tip, sometimes farther back
54
root epidermis
formed from protoderm, which differentiates into epidermal cells and root hairs
typically 1 cell layer thick
some species develop layered, complex epidermis for water absorption and storage
ex: aerial roots on orchids
55
root hairs
single cells, pectin and cellulose walls
sticky: adhere to soil
short lived, constantly regenerated
most root surface area is on root hairs
site of nutrient absorption
56
cortex
derived from ground meristem
mostly parenchyma cells
endoermis
casparian strip
exodermis
57
endodermis
cortex
innermost layer
single cell
thickness
regulates mineral absorption
58
casparian strip
cortex
waxy protective layer on walls of endodermal cells
59
exodermis
cortex
additional cell layer with casparian strips adjacent to dermis in some species
60
vascular cylinder
central section to root
develops from procambium
primary xylem in central core/ring
morphology is different in monocots vs eudicots
monocot=ring with pith
dicot=core
61
xylem development
protoxylem
metaxylem
thick cell walls with pits for lateral transport
protoxylem can be crushed at metaxylem development
62
protoxylem
first xylem to mature
outer layer
can transport water while roots elongate
flexible
63
metaxylem
last xylem to mature
inner layer
matures after elongation is complete
rigid
64
phloem
forms between protoxylem arms
protophloem: first phloem to mature, functions during elongation
metaphloem: forms later, functions during maturity
65
pericycle
outer border of the vascular cylinder
single cell layer
site of lateral root formation
contrubutes to vascular cambium formation and cork cambium formation (Not in monocots)
66
secondary growth in roots
initiated by division of pericycle cells and residual procambium cells
- vascular cambium forms inside pericycle
- increasing secondary growth causes pericycle to split and destroy epidermis
- pericycle converts to cork cambium, initiates bark growth
67
rhizobium
n-fixing bacteria
infect legume roots
form nodules
allows plants to use atmospheric nitrogen that would normally be unavailable
68
mycorrhizae
fungus root
found in 90% of plants
improve nutrient absorption (Phosphorus)
fungi get carbon from plants, plants benefit from increased root surface area, water, nutrient uptake
69
arbuscles
tree like structures within cells
found in most plant families
fungal hyphae penetrate plant root cells, branch
70
ectomycorrhizae
form fungal mantle covering outside of roots
EM fungi dont penetrate root cells
found in pine, oak, birch families
71
shoot system
stems support leaves, flowers, fruit
conduct water from roots, sugars from leaves
leaves are considered part of shoot system, but a separate organ from stem
72
stem module
leaf
bud
segment of internode
73
internode
section of stem between nodes
74
node
point of attachment of different modules
buds and leaves found at nodes
75
shoot apical meristem
cell division
development of other meristems
76
protoderm (shoot)
outermost meristem
becomes epidermis
77
ground meristem (shoot)
center of shoot tip
becomes pith and cortex
78
procambium
becomes xylem and phloem
79
dicot stem anatomy
xylem and phloem arranged in vascular cylinder
primary xylem to inside
primary phloem to outside
central pith (ground tissue)
leaf trace: vascular bundle that enters leaves
80
monocot stems anatomy
term: atactosteele
vascular bundles scattered through ground tissue
some have hollow stems
most dont develop secondary growth
primary thickening meristem: contributes to elongation and thickening, allows monocot stems to be same diameter at base and tip
81
woody plants secondary growth
originates in vascular cambium
cell division orginates in residual procambium
fascicular and interfascicular cambium form a complete ring of vascular cambium
82
fascicular cambium vs interfascicular
fascicular: residual procambium cells in bundles
interfascicular: cells between bundles
83
how do woody plants develop secondary vascular tissue
vascular cambium divides in 2 directions:
secondary xylem forms inside
secondary phloem forms outside
fusiform intials: (longitudinal transport)
ray intials (radical transport)
84
fusiform initials
vascular camboum cells that develpo axial system, including vessel members
longitudinal transport
help develop seconary vascular tissue
85
ray initials
vascular cambium cells that form the ray system, including ray parenchyma and ray tracheids
radical transport
help develop secondary vascular tissue
86
annual rings
yearly growth of secondary xylem
87
dendrochronology
use of tree rings to study past ecology
climate distrubance human activity
88
springwood/earlywood
large cells from spring growth spurt
89
summerwood/latewood
smaller cells from later season growth
90
woody stem anatomy
heartwood
tyloses
sapwood
knot
91
heartwood
dead secondary vascular tissue
often blocked with resin or other cells
92
tyloses
parenchyma cell grows into vessel, blocking ti
93
sapwood
functioning xylem in woody stem
94
knot
embedded base of old branch
95
categories of vessel structure for wood
ring porous wood
diffuse porous wood
different responses to water stress
96
ring porous wood
large diameter vessels located mostly in springwood
ex: oak, hickory
97
diffuse porous wood
large diameter vessels located throughout
ex: maple, elm
98
gymnosperm vs angiosperm wood
gymnosperm: mostly tracheids, simple rays, resin ducts
angiosperms: multiple cell types, complex grains
99
bark
derived from periderm
all tissues from vascular cambium to stem exterior
100
secondary phloem
forms to outer side of vascular cambium
101
periderm
cork cambium
phellem outside na dphelloderm inside
phelloderm is waxy, protective
102
lenticel
loose parenchyma cluster for gas exchange
in bark
103
buds
compressed branch leaf or flower
bud scales: modified protective leaves
leaves and vascular bundles leave distinct scars: leaf scar, bundle trace
bud scale scars separate annual growth
104
tubers
enlarged underground stems
allow storage
ex: potato
105
corms
short underground stems with thin, paper like leaf coverings
allow storage
106
bulbs
small modified stem surrounded by thickened storage leaves
allow storage
ex: onion, crocus
107
stolons
horizontal above ground stems
allow vegetative spread
ex: strawberry
108
rhizomes
below ground horizontal stems
allow vegetative spread
ex: iris, ginger, grasses
109
modifications to shoots defend plants
thorns: stem growth in leaf axils
spines: modified leaves (not stem tissue)
prickles: cluster of modified epidermal cells
110
facultative vs obligate parasites
obligate: require host to grow and complete life cycle
faculative: do not require host
111
parasitic plants obtaining carbon
obtain from hosts instead of photosynthesis
parasites tap into host vascular tissue with haustoria
can attach to roots or stems
112
haustorium
rootlike absorbing organ
can arise from root or stem tissue
allow parasites to tap into vascular tissue
113
holoparasitic plants
have no chlorophyll
obligate, all carbon from hosts
often unusual colors (yellow, red, brown)
may be only visible when flowering
114
beechdrops
parasitic on american beech roots
holoparasitic ex
115
bear corn
holoparasitic ex
paraistic on red oak
116
one flower cancer root
holoparasitic ex
parasitic on many species
117
hemiparasitic plants
photosynthesize and parasitize
facultative or obligate (some carbon from hosts)
often green and have leaves
ex:
- mistletoe: tree branch parasite
- wood betony: grass root parasite
118
parasitic plants and biodiversity
may be important food for animals
parasitism can prevent competitive species from dominating
betony in prarie restorations = more diversity
119
rafflesia arnoldii
largest flower
found in sumatra and bornero
parasitizes one species
also a carrion flower: odor mimics rotting meat
120
beechdrops and history
beechdrops are limited to old forests with large beeches
beech is slow growing
bear corn also requires large individual host trees
121
large trees and age
large trees do not mean old forest
122
mycoheterotrophic plants
obtain carbon from fungi
3 way relationship between green plants, fungi, and non-photosynthetic parasite
1. plants obtain carbon from photosynthesis
2. mycorrhizal fungi trade nutrient absorption from carbon
3. chlorophyll-less plants take carbon from fungi
only visible at flowering
123
mycoheterotrophs in pittsburgh
ghost plant
pinesap
coralroot orchids
124
carnivory
plants eat insects with their leaves to obtain nutrients
most also photosynthesize
common in nutrient-poor habitats
nitrogen and minerals from insects
multiple mechanisms to trap prey
125
pitcher
modified leaf containing digestive enzyme
insects may be lured by fragrance and fall in
passive mechanism of carbivory
126
nepenthes lowii
shaped like a toilet
obtains nitrogen from shrew feces
127
trap leaves
sticky mucilage adhesive traps prey
insects difested on leaf surface
ex: sundrews, butterwort
passive mechanism of carnivory
128
active mechanism of carnivory
snap trap
bladder traps
129
snap traps
motion of prey triggers closure
trap close after motion of 3 trigger hairs
ex: venus flytrap
130
bladder traps
generate vacuum via ion pumping
trigger hairs open trap, release vacuum
ex: bladderwort
131
flying ointments
said to be used in witchraft
cause delirium
132
leaf functions
photosynthesis
thin leaves = ample surface area for light absorption
transpiration leads to water loss
133
leaf structure of simple leaves
blade
petiole
midrib
may be lobed
ex: oak, maple, elm
134
blade
photosynthetic area of leaf
135
petiole
stalk that holds leaf up
allows movement
136
midrib
central vein of leaf
137
leaf structure compound leaves
divided into multiple leaflets
each leaflet is a subunit of leaf blade
rachnis: central axis
ex: walnut, hickory, buckeye
138
pinnate compound
leaflets along central axis
139
bipinnate compound
leaflets along veins emerging from central axis
140
palmate compound
leaflets arranged from a single point
141
leaf structure of monocot leaves
parallel veins
sheath: leaf base wrapping around stem
ligule: tissue extending upward from leaf, over stem
intercalary meristem: site of cell division at base of leaf, allows continuous growth
142
heterophylly
multiple leaf shapes per plants
143
leaf shape and light
shade: wider, more surface area
sun: narrower, more dissected
144
leaf shape age
changes at maturity
ex: english ivy
145
phyllotaxis
leaf arrangement
opposite: leaves opposite on stem
alternate: leaves alternate on stem
whorled: 3 or more leaves on one node
spiral: leaves arranged in spiral along stem
146
epidermis of leaf
outer layer
composed of a single cell layer
site of gas exchanage and protection
epidermal cells, guard cells, subsidary cells, trichomes
147
stomata
openings in leaf surface
allows gas exchange
bordered by guard cells that allow opening and closing
typically on leaf undersides to minimize water looss
1000-1000s of stomte per square cm
148
trichomes function
defense: secondary compounds to deter herbivory
heat protection: thick layer of white/silver hairs to insulate and reflect light
carnivory: trichomes with adhesives
149
photosynthesis leaves
occur in mesophyll: parenchyma cells with chloroplasts
chloroplasts photosynthesize and move within cells
150
mesophyll tissue
palisade meosphyll
spongy mesophyll
substomatal chamber
151
palisade mesophyll
paslisade parenchyma closely packed for light exposure
152
spongy mesophyll
spongy parenchyma with air spaces for gas exchange
153
substomatal chamber
air space near stomata
exposed cell walls allow for gas exchange
154
veins in leaves
transport water and nutrients
vascular tissue extends into leaves where the xylem is near upper surface and phloem near lower surface
vascular tissues are surrounded by collenchyma for support
155
xerophytes
found in dry habitats
- stomatal crypts: sunken stomata within leaf
thick cuticles: waxy coating prevents waer loss
fibers: help leaves retain shape in drought
succulence: water storage in leaf or stem
ex: agave, jade plant, oleander
156
hydrophytes
found in awuatic habitats
- thin leaves and cuticles: no need to conserve water
- stomata on upper leaf surface of floating plants
ex: water lily, pickerelweed, skunk cabbage, water hyacinth
157
modified leaves types
purpose: support and defense
tendrils
spines
bulb scales
158
tendrils
modified leaves or leaflets that wrap arround support
allow plants to climb
159
spines
hardened leaves or stipules for defense
160
bulb scales
below ground storage leaves attached to bulbs
modified branches
161
leaves as organs
temporary: limited life spans and fall off
hormonal signals cause nutrients to return from leaf to stem
vascular tissues are pluguged
leaaves fall off, sbcission layer hardens for protection which forms leaf scar
162
abscission
leaf separation
abscission layer: specialized weak tissues
163
traits of true fungi
heterotrophic: nutrients from environment, do not photosynthesize
chitinized cell walls
reproduction by sporces
sporce cell walls protect from dehydration
164
fungal body
thallus
mycelium
hyphae
165
thallus
fungi
body composed of multiple cells without specialized conducting tisusues
166
mycelium
fungal thallus of branched hyphae
167
hyphae
filaments, make up mycelium of fungi
can be microscopic but become visible when aggregated
growth occurs at tips of hhyphae
168
chemotrophism
growth toward food in response to chemical signals for fungi
169
feeding and digestion of fungi
digestive enzymes are secreted at tips of hyphae
fook upate via active transport: water enters hyphae via osmosis
water pressure causes hyphae to expand and extend deeper into food source
170
fungal nutrient transport
transported via pressure gradients
fungi feed via absorption through cell walls
171
cytoplasmic streaming
controlled flow of particles
nutrient transport in fungi
172
septa
cross walls of hyphae
sepatal pore: openings to allow transport of nutrients
173
asexual reproduction in fungi
mitospores
conidia
conidophores
in many species, sexual reproduction has never been oberved
174
mitospores
small parts of parent fungus
175
conidia
spores formed at the tips of hyphae
176
conidoophores
spore bearing hyphae
177
parasexual cycle
hyphae fuse
nuclei mingle without meiosis
178
heterokaryotic fungi
contain more than one genotype
179
haploid state of fungi
possible with chromosome loss
180
meiospores
sexual spores with genes from two parents
fungi
produced through meiosis after 2 different individuals fuse
nuclei fuse --> undergo meiosis --> produce recombinant spores
genetic variation: survival in diverse habitats
181
mycorrhizae
symbiosis with palant roots and fungi
182
microbial communities
in ruminant animals
fungi assist with digestion
183
leafcutter ant fungal farms
fungi grow on leaf pieces
tended by ants
dispersed with new nest construction
184
pathogens
mostly parasites or pathogens of plants
185
saprobes
decomposers
feed on decaying organic matter
186
fungi multiple lifestyles
some fungi can be both pathogens and saprobes
wood decay fungi may kill trees and continue feeding on dead wood
187
fungi phyla
chytridiomycota
scomycota
basidiomycota
zygomycota
glomeromycota
188
chytridiomycota
fungi phyla
1000 named species
flagelleated swimming cells
found in wet habitats
sexual reproduction: unkown
decomposers: digest algae and plants
189
zygomycota
fungi phyla
1100 described species
saprobes and parasites
sexual and asexual reproduction
ex: rhizopus stolonifer
190
ascomycota
cup fungi
32000 named species
both sexual and sexual (conidial) stages
ascoma: fruiting body
ascus: meiosporangium
ascospores: meiospores producued in ascus
191
ascomycete diversity
penicilloum: kitchen molds, used in cheese
bakers yeast: bread, beer
aspergillus: kitchen mold, dangerous but some useful for food production
powdery mildew: plant pathogen
192
lichens
symbioses of ascomycetes with algae or cyanobacteria
135000 species
lichens named for fungal partner
many growt forms found in all ecosystems
193
glomeromycota
arbuscular mycorrhizae
sexual production: unkown
asexual: mitospores at tip of hyphae, not in sporgania
large spores 1mm)
early plant fossils contain them
194
basidiomycota
26000 named species
produce largest fruiting structures
mushrooms, rusts, smuts
decomposers, pathogens, mycorrhizae
195
hymenomycetes
type of basidiomycota
14000 species
sexual fruting bodies, primary sexual
mushrooms, bracket fungi
many are mycorrhizal or saprobes
196
urediniomycetes
type of basidiomycota
rust diseases: complex life cycles with alternate host plants
major plant diseases
ex: wheat rust, cedar apple rust
197
ustilaginomyctes
smuts and hutilacoche
host specific
198
smuts
type of ustilaginomycetes (basidiomycota)
pathogens of green plants
produce masses of black hyphae
199
hutilacoche
type of ustilaginomycetes (basidiomycota)
mycelia take over corn kernals
hijak development
200
slime molds
protists, not fungi
no chitin in cell wall
produce sporangia
plasmodium: aggregate of undivided cytoplasm, many nuclei
may be plasmodial or cellular
many taxanomic groups
201
basidiomycota types
hymenomycetes
urediniomycetes
ustilaginomycetes
