Exam 4 Flashcards
flowering plants
- monocot and dicot (eudicot)
- have fruits and seeds
- roots
- stems and leaves (shoots)
- flower
nonflowering plants
- naked seeds (pine)
- spores (fern and moss)
vascular plant systems
- root system
- shoot system
root system
- anchors plant, absorbs water and nutrients
- have root hairs, lateral roots, and no nodes
shoot system
- supports leaves for photosynthesis (without there would be no leaves)
- conduct sugars and h2o back and forth
apex
tip where growth occurs (in roots and stem)
tap root
one large main root that gets water from deep in the ground (dandilions)
fibrous root
shallow roots with lots of branches that collects rain
grass
epiphyte
plant on a plant (aerial root to get more sunlight) that don’t form roots in soil
-thick and spongy roots
modified root
special structure for better function
- storage of carbohydrate nerves (vegetables with starches and sugars)
- parastic roots-climb up trees and suck out nutrients (mistletoe)
- oxygen absorbing- extension of root to get oxygen when the tide comes in (pneumatophore)
- aerial root- orchids, epiphyte (dont hurt host)
- root nodules- n-fixing bacteria; symbiosis
symbiosis
plant benefits from bacteria and bacteria benefits from plant
adventitious roots
- root that emerges from stem
1. prop roots- help tall plants from falling (corn)
2. stilts (shallow soil)
3. buttress- widening at base (shallow soil)
Stem consists of:
- shoot apex/tip
- axillary bud
- internode
- node
- young leaf
axillary bud
a bud where the stem meets the petiole
node
where leaves are attached
Runner/stolom
modified stem that goes across horizontal surface with adventitious roots
-strawberries
rhizome
modified stem thats thick and underground with adventitious roots
stolon with tubers
modified stem with specialized underground stem tissue
stolon-branches
tubers-tips
-potato
bulb
modified stem thats short and thick with adventitious roots
-onion (rest is leaves)
corm
modified stem thats broad and thick
-papery leaves
tendril
modified climbing stem
-grape vines
cladophyll
modified photosynthetic stem
-cactus and snake plant
monocot
parallel veins
dicot
branched veins
simple vs compound
simple- one leaf on petiole
compound- multiple leaves on petiole
-pinnate- rows
-palmate- like fingers on a hand
succulent
modified leaf thats thick and spongy and stores water
-aloe
spine
modified leaf that is for protection (no photosynthesis)
-cactus
window
modified leaf that if underground with windows for photosynthesis bc its hot
reproductive leaves
modified leaves that can grow independently
flower pot
modified leaf that form place for roots to grow
carniverous
modified leaf
-venus fly trap, sundew, pitcher, bladderwort
bracts
modified leaf that help attract pollinators
-poinsetta
tissues
ground- body of organ, storage, photosynthesis
vascular- transporting material (xylem and phloem)
dermal- outer layer of specialized cells (epidermal cells)
ground tissue
parenchyma- thin primary cell walls; live (stems, leaves)
collenchyma- thick primary cell walls; live (petiole)
sclerenchyma- primary and secondary cell walls; dead
primary cell walls
-cellulose
-hemicellulose
-pectin
-HRGP
(flexible, strong, porus)
secondary cell walls
everything and lignin to make it harder
-inside of primary cell wall
cellulose
polymer of glucose; beta 1,4 linked
-cellulose microfibril- bundle of cellulose to make it stronger (chains of glucose together)
hemicellulose
half glucose
half zyloglucose or aratinogalactin
-anchoring embedded on surface of fibrils (attaches pectin)
HRGP
hydroproline rich glycoproteins
- amino acid proteins
- arabinose is the sugar
lignin
- polymer of sinaphyl or conipheryl alcohols
- ring shaped network
sclerenchyma
- sclerids (astrosclerdid- star shaped; form nutshell)
- fibers- are long and thin (protect vascular bundle; money not cotton) usually enforcing stem
- have secondary cell walls
cotton
not fibers, made of cellulose trichomes
xylem
- has vessels, tracheids, and secondary cell walls (lignin)
- dead
- no cytoplasm
- carries water
- simple and bordered pits
phloem
- sieve tube cells and companion cells
- active metabolism (mitochondria)
- transport sap
- live
- only primary cell wall
- companion cell to keep sieve tube cell going without nucleus
simple vs bordered pit
simple- allows transfer of water from one cell to another
bordered- has torus that can seal border of secondary cell wall
middle lamella
- glues cells together
- made of pectin
root epidermal cell
root hairs- increase surface area
stem epidermal cells
trichomes: -hairs -white and reflective for overheating -prevent water loss glandular trichome- oil to prevent water loss
leaf epidermal cells
- cuticle- cutin made of wax (not cellular)
- trichomes
- guard cells
guard cells
have bands of cellulose to absorb/lose water
- in stoma
- opens to pump potassium and water follows
woody dermal layer
- cork
- cork cambium-produces new cork
- phelloderm
- periderm
- lenticles- openings in bark for gas exchange
sap
full of sugars of photosynthesis
transpiration process
evaporation of water through stomata
- capillary action- cohesive liquid in narrow capillary/xylem (long chain that won’t break)
- evaporation- opens guard cells; water leaves in vapor form
- tension- when one water molecule leaves it pulls whole chain
plasmodesmata
membrane lined channel
-move things from cell to cell
apoplast
non living parts of plants
-cell wall
apoplast route- movement through cell walls and space b/w cells
symplast
living parts
-cytoplasm and membranes
symplast route- cytoplasm continuum b/w cells connected by plasmodesmata
transmembrane routes
transport through the aquapores
osmosis
absorption at root; root pressure (pushes water up xylem)
-apoplast
aquaporin
protein that get water across plasma membrane
guttation
oozing out of water from pressure
casparian strip
- in endodermis
- stops waters apoplast transport
- lipid and lignin (suberin)
water transport
- osmosis (apoplast)
- stopped by casparian strip
- goes transmembrane route to get into cytoplasm (symplast)
- only goes up
phloem transport
-transports sugars - sucrose, glucose, fructose
-distribute carbohydrates produced by leaves
bidirectional- can go up or down with input of energy
aphid
phloem feeding insects with stylet to feed
pressure-flow theory
a model describing the movement of carbohydrates in phloem
-active loading and unloading
phloem loading
active process of putting sugar into the phloem
- happens at source (leaf)
- symport H+
companion cells
does the work for active transport in phloem
-has nucleus and mitochondria
soil
topsoil- most roots; mixtures of minerals
organic- from living things
inorganic- minerals
inorganic soil
sand- 1mm-.05mm (well drain, poor hold)
silt- .05mm- .002
clay- .002 or less (poor drain, good hole)
loam
mixture of 40% sand, 40% silt, and 20% clay
organic soil
humus- partly decayed plant matter
- amino acids
- carbohydrates
- tannins
soil profile
- topsoil (high organic materials)
- subsoil (high organic materials)
- bedrock
macronutrients
need large amounts; building blocks -C, O, H, N, S, P K- guard cells- active transport CA- cell wall; binds w pectin MG- chlorophyll and lipids -proteins, lipids, nucleic acids, carbohydrates
micronutrients
- need small amount
Cl, Fe, Mn, Zn, B, Ca, Mo
testing for nutrient deficiency symptoms
plant is floating in air with root in nutrient bath
mobile elements
moves to new leaves making old leaves deficient
-N, P, K, Mg
immobile
stays in old leaves making new leaves deficient
-Ca, Zm, B, M, Fe
deficiencies
nitrogen-chlorosis or it turns yellow (old) calcium- distorted/wrinkled (new) potassium- wilting copper- stunted growth iron- interveinal chlorosis
fertilizers
N, P, K
NO3, NH3
meristems
shoot- apical; stimulates tall growth root- makes root grow down thickening- cork and vascular cambium (dicots and woody plants) -not in monocots bc of scattered bundles basal- on the bottom (grass)
clay structure
crystalline lattice of net negative charges
- rain doesn’t wash away nutrients
- binds to positive cations (H+)
- SiO4 and AlO4
Cation exchange (CEC)
plant root releases acid or H+ which switches places with cation and the cation goes into root
- uses active transport in epidermal cell membranes to move cation across plasma membrane
- costs atp
History of Auxin hormone
1881: charles and francis darwin grew canary grass and discovered phototropism (plants grow towards light) and tip is sensor
1926: Fritz Went
-came up with name auxin
-cut off tip of oat seed and put it in agar block in dark and curvature still happened bc chemical signal
(side with light= cells don’t elongate)
auxin names
indole acetic acid (natural) synthetic -IPA -NAA -IBA -24D (herbacides)
activities of auxin
- fruit formation
- leaf abscision (auxin prevents it)
- apical dominance (shoot apex wants it to grow up, but if cut it has bushy growth)
- stimulate root growth
- cell elongation
cytokinin history
1955 Skoog Miller
wanted to stimulate cell division (UW madison) and used herring sperm to stimulate growth of carrot and only the old sample with broken down adenine (kinetin) worked
cytokinin names
- zea (corn) has zeatin (natural cytokinin)
- cytokinin bc cytokinesis
- BAP and ZIP (synthetic)
cytokinin activities
- cell division
- stimulates shoot growth and auxiliary bud
- senscence: shutting down and death of leaf (cytokinin delays it)
- leaf expansion
Gibberellin history
1809 in japan rice plants grow too tall (foolish seedling disease; baknae) caused by fungus gibberellin
1925 kurosawa heated growth medium of fungus and filtered the liquid into plant to induce growth making it a steroid (bioassay- looking for chemical)
-bean seeds first natural occurring (GA1)
Gibberellin activities
- flowering (cabbage fam-produce stalk)
- internode elongation
- stimulate seed germination (grain + barley)
- seedless grapes
Barley germination
- imbibe- seed absorbs water
- embryo releases gibberellin
- aleurone layer (inside starch endosperm) releases amylase to break down starch
Abscisic Acid (ABA)
1949- dormant buds (thought is was dormin but it was ABA)
1965- leaf abscission (ABA does it)
synthesized in mature leaves, root caps, base of fruits
Abscisic Acid activities
- close guard cells
- fruit drop
- leaf abscission
- dormancy (seeds and buds)
- precocious sprouting- seed germinates on parent plant
Brassinosteroids
synthesized in pollen and many tissues
- cell elongation and division
- apical dominance
- root and pollen tube growth
- seed germination
oligosaccarins
-long chain sugars (technically not a hormone)
-released from plant cell walls
Activities
-plant defense- kill injured part of leaf w localized neurosis (growing and dying)
-inhibit stem elongation
Ethylene history
-gaseous hydrocarbon found in natural gas
-trees dropped leaves and premature fruit when next to street lamp
1901
-pea seedswith gas normal growth didn’t happen
-demetri neljubor took apart gas and found ethylene
ethylene activities
synthesized in ripening fruit and damaged tissue
- leaf abscission
- fruit ripening
- wound repair (suberin-water proof lipid)
- inhibits lateral buds and stem elongation
ubiquitin
protein that tags cell after auxin so proteosome can act
proteosome
protein body with hollow structure that degrades
- molecular garbage can
- after ubiquitin
how auxin works
- auxin goes to TIR (auxin receptor)
- SCF becomes ARF (response/transcription protein)
- ubiquitin goes to Auxin protein inhibitor and degrades it
- ARF activates genes
how gibberellin works
- gibberellin goes to GID1
- SCF (degrading factor) releases and degrades della (inhibitor)
- GA-TRXN becomes active transcriptor
etiolation
plants grow in dark (no chlorophyll and tall)
Hendricks Borthwick
1954 took separated etiolated plants and gave them each diff wavelengths of light to find the receptor
- red light turned normal
- Far red did not work
- Phytochrome red- red absorbing (inactive in light)
- Phytochrome far red- active (730nm of light becomes inactive)
phytochrome
blue pigment in membranes
photomorphogenesis
where plant growth patterns respond to the light spectrum
flowering
- light and dark dependent
- gibberellin dependent
- temp
- automonous
photoperiod
length of light
day neutral plants
close to equator
-corn, rice, peas
long day plants
flower with exposure to long days; spring/summer
-tobacco, ragweed, and poinsettia
Hamner and Bonner
used cocklebur (short day) to test schedule and it didn’t flower if it didn’t have long enough nyctoperiod
- shortened days (16 hours) and interrupted days didn’t work
- phytochrome is cause
Pfr
Pr going to Pfr is activating
-binds to ubiquitin in dark and degrades
