Test 2 Flashcards
apical meristem becomes
flower
angiosperms
monocots and dicots
4 sets of leaf primordia (4 whorls)
sepals
petal
stamen
pistil
sepals
leaf primordia modified for protecting inside (surround petals)
calyx
sepals together
petal
colored to attract pollinator
corolla
petals together
stamen
boy part
produce pollen which contains sperm
anther and filament
anther
produces pollen
filament
support
androecium
stamen together
pistil
female parts
has eggs
ovary, style, and stigma
gynoecium
pistils together
ovary
where eggs are produced
style
support
stigma
bulb
perianth
sepals and petals together
complete flower
has all 4 whorls
incomplete flower
lacks at least 1 of 4 whorls
perfect flower
has both male and female parts
imperfect flower
has only male or female parts (entirely male or entirely female)
staminate
entirely male flower (imperfect)
pistillate
entirely female flower (imperfect)
monoecious plant
male and female all on 1 plant
corn
dyoecious plant
2 separate plants
1 male plant and 1 female plant
marijuana
inflorescences
flowers on the branches
pollination
act of moving pollen to receptive location
self-pollination
flower that can accept its own pollen
cross-pollination
leads to more variety of genes
plants have biochemical blocks (rejects its own pollen)
if its own pollen lands on it, it won’t grow
pollination vectors
means by which pollen gets where it needs to go
kinds of pollination vectors
animal
inanimate
kinds of animal pollination
insects
birds
bats
kinds of insect pollination
beetles bees butterflies moths flies
beetles means of pollination
crawlers and chewers
beetle pollinated flowers=large (southern magnolia)
don’t respond to color much
beetles want nectar
possible reason for inferior ovary
beetle damage
coevolution of flowers
crude insects (beetles) evolved with old flowers sophisticated insects (bees) evolved with sophisticated flowers
bees means of pollination
fly and land on flowers (landing platform)
responsive to color (see contrast between light outside and dark inside–nectar guide)
when bee lands on landing platform in pulls stamen down and hits them on head leaving pollen
constancy
as long as nectar holds out bees will continue to go back to same flowers
butterflies means of pollination
day fliers (land on edge of flower) ROY flowers stick tongue down to get nectar
moths
night fliers (hover, don't land) bright white flowers, open at night, and tube like
flies means of pollination
like bad scents
bird pollination
hummingbirds
like nectar from same flowers as butterflies (ROY)
color attracts them because they can’t smell
bat pollination
not technically blind but don’t see well
nocturnal
white, large, open at night, with certain smell (fruity/overripe fruit)
land in flower and eat nectar and pollen
desert (cactus) and rainforests use bat pollination
types of inanimate pollination
wind
water
wind pollination
end up at correct place by mere chance
flower has no smell or color (produces as much pollen as possible instead)
typically imperfect
reproduce by catkins (male flowers on wand hanging down with a few female flowers at end) –pine trees
takes place before canopy is set
occurs with trees growing in blocks (pollen travels next door)
water pollination
ex: valisneria
1. female attached by root to part underwater and male floats up (not attached)
2. male and female come together for pollination
3. male floats off and female pulled under
radial symmetry
petals all the same size
bilateral symmetry
one bigger petal (landing platform)
hypogynous with superior ovary
ovary above
apples, pears
perigynous with superior ovary
ovary sitting in open cup (not fused) above other parts pit fruits (peaches, plums)
epigynous with inferior ovary
ovary attached to cup
below other parts
hypanthium surrounds ovary
microsporocytes
pollen sacs
beginning cells
make pollen
diploid
anther fertilization
- pollen sacs (microsporocytes) undergo meiosis (now have 4n microspores)
- 4 microspore divide mitotically to give 8n (pollen grains)
cell walls of pollen grains
- intine (inner): made of cellulose
2. exine (outer): made of sporopollenin (very tough)
pollen grains
generative cell (splits and forms 2 sperm cells) tube cell (leads way down to ovary--drills down)
ovary fertilization
- egg divides meiotically
- 3 spores closest to gap abort (1 functional megaspore)
- undergoes 3 mitoses (8 products)
- 1 cell from each side moves to the middle (3 on each side and 2 in the middle)
- separate tube and generative cells come down to ovary through pollen tube (tube cell aborts when it reaches ovary)
- 2 sperm in generative cell (one joins egg to form embryo, other joins polar nuclei to give endosperm)
- embryo surrounded by endosperm with thick seed coat (seed in fruit) all inside ovary (whole thing becomes fruit)
berry
fleshy pericarp
ovary wall fleshy and containing 1+ carpels and seeds
simple
blueberries, grapes, cranberries, tomato, peppers, etc
pepo
berry with ovary wall a hard rind
simple
watermelon, pumpkins, all melons
separate male and female parts on same plant
hesperidium
berry with ovary wall a leathery rind
simple
oranges, lemons, limes (citrus)
drupe
only a portion of pericarp fleshy
simple
exocarp thin, mesocarp fleshy, endocarp stony, single seed and carpel
avocado, plum, peach, apricot, nectarine, coconut, etc.
pome
outer portion of pericarp fleshy inner portion papery floral tube fleshy several seeds and carpels apples, pears, pomegranetes
types with fleshy pericarp
simple
types with dry pericarp
dehiscent and indehiscent
simple
berry (pepo and hesperidium)
drupe
pome
dehiscent
*pops open at maturity* legume follicle capsule silique
indehiscent
*doesn't pop open at maturity* samara schizocarp caryopsis/grain nut achene
one-seeded indehiscent fruits
caryopsis/grain
nut
achene
legume
composed of 1 carpel
splits along 2 sutures
edamame, green beans, peas, peanuts (indehiscent)
follicle
composed of 1 carpel
splits along 1 suture
capsule
composed of 2+ carpels
dehiscing in 1 of 4 different ways
opium poppies, okra
silique
composed of 2 carpels
separate at maturity and leave a persistent partition wall
samara
pericarp bearing winglike growth
leaves of maple tree (spin down when they fall)
schizocarp
pericarp doesn’t bear winglike growth
2-many carpels
united when immature
split apart at maturity
caryopsis/grain
one carpel
if more doesn’t split apart at maturity
one seeded
corn, rice (carbs)
nut
seed not united to pericarp all around
large fruit with thick stony wall
walnut, pecan
achene
seed not united to pericarp all around
small fruit with thin wall
sunflower seeds
aggregate
fruits formed from several ovaries
develop from 1 flower
strawberries, blackberries, raspberries
multiple fruits
fruits formed from several ovaries
develop from many flowers
pineapple, fig
plant domestication
changing characteristics to fit what we want in final product
plant becomes reliable on humans for growth and have therefore lost fitness
ex: corn (dependent on humans for reproduction)
fitness
ability to pass genes on to next generation
Decandolle
“The Origin of Cultivated Plants”
used historical linguistics to trace food lineage back to where they started
quinine
first medicine
comes from bark of tropical tree
china
rice, millet, soybeans, bamboo, tea
india
meat, barley, dates, cotton
mesopotamia
wheat, barley, lentils, peas (english), olives, dates, grapes, flax (linen)
salinization
land becomes saltier the more it is used and irrigated (as water dries the salt is left behind)
wheat very intolerant to salt
wheat -> wheat and barley -> barley -> nothing
egypt
wheat, barley, lentils, english peas, olives, dates, grapes, flax (linen) (SAME AS MESOPOTAMIA)
agriculture based on flooding of the Nile River
tropical asia
mango, citrus, tarro, coconut, banana
central africa
sorghum, okra, yams, black eyed peas, coffee
*brought into the US to feed slaves
western hemisphere (US, Mexico)
corn, beans (various kinds), peanuts, cotton, peppers, tomatoes, tobacco, chocolate, pineapple, pumpkins, squash, avocado, potatoes, sunflower, manioc, rubber, vanilla
seed
dormant plant
steps of germination
- water absorbed and seed coat bursts (inhibitor compounds washed out)
- oxygen: feeds mitochondria (very energy consuming activity) and aerates soil
- temperature: cold temp. causes compound inhibitors to break down by freezing and thawing
* 1, 2, & 3 ONLY THINGS NEEDED - light: some plants only germinate with light
- fire: seeds will have no competition if fire has come through area (Jack Pines need this)
- digestive enzymes: some seeds have to pass through digestive tract of animal so seed coat can break down
hilium
scar on seed
micropyle
hole (break in integuments)
allows oxygen across seed coat
hypocotyl region
first out when seed coat bursts
“hypocotyl hook”
tough and pulls plumule up after
coleoptile
protective sheath around plumule
coleorhiza
protective sheath around radicule
direction of growth of plumule and radicule
plumule grows up
radicule grows down
how is popcorn made
water molecules explode and turn embryos inside out
bran
talks about pericarp and aleurone layer
has vitamins and lipids
provides fiber for a diet
germ
embryo
contains a lot of lipids and oils
total number of flowering plants (angiosperms)
235,000
number of angiosperms that have been cultivated
150
6 plants that 80% of calories consumed come from
corn wheat rice potatoes sweet potatoes manioc
14 most consumed plants
corn, wheat, rice, potatoes, sweet potatoes, manioc, sugar cane, sugar beets, pinto beans, soy beans, barley, sorghum, coconut, banana
*grown today on very large scale
problems with todays agriculture
- 9 kcal of energy to get 1 kcal of food
- soil erosion (every time field is plowed it is open to wind and other elements and erosion occurs
- salinization
ways to improve todays agriculture
crop improvements new crops seed banks transgenic plants medicinal plants ethnobotany
crop improvement
- grow 14 more efficiently with more yield and higher nutrient content
1. hybrid corn
2. triticale
3. green revolution (not as efficient)
hybrid corn
combines 2 pure strains of corn to get perfect hybrid
more uniform and efficient crop (no genetic variation)
problem: whole crop wiped out if disease strikes
triticale
triticum (wheat) and secale (rye)
can be grown in many more places than wheat but with lower yield
new crops
- especially new carb and protein sources
1. jojoba: SW america (plant that saved the whales)
2. guayule: latex found in stems
3. grain amaranths: brought back (produces protein)
seed banks
save seeds of all known crops in world today
1 in each country (each focuses on their major crops and indigenous crops)
backup in case of disease
US: wheat and corn
transgenic plants
take crop plant and add genes (by splicing) from some other source
GMOs: genetically modified organisms (very controversial)
medicinal plants
doctrine of signatures (universal idea)
Herbals: huge book with all ideas of doctrine
doctrine of signatures
- god is great/all knowing
- people are stupid
- god provided stupid humans with signatures about what plants are good/bad
ex: lobed leaf for liver, walnuts=brain
* not necessarily true
ethnobotany
fusion of anthropology and botany
ethnobotanist sits down with tribes to learn about their plants and medicines
ex used today: curare, sangre de drago, una de gato
curare
from someone studying poison of poison dart
causes paralysis of muscles
used in surgery
sangre de drago
used to seal wounds (latex)
true antiseptic
una de gato
“cat’s claw”
grows as a vine and climbs using claws on branches
used for tea
nutritional needs
CO2, H2O, minerals, light
minerals
macro and micro
macro
needed in great amount
C H O P K N S Ca [Fe] Mg (Si)
Si recently added
Fe moved to micro
micro
needed in smaller amounts
trace elements needed to catalyze reactions (can be reused over and over again)
Fe now micro element
water
greatest need of any plant
absorbed and lost in transpiration (leaves through open stomate)
ions pumped in by ATP through root hairs and water follows
soil needs to be well aerated so there is O2 present to be used by ATP to push ions across
cohesion-adhesion-tension theory
H2O molecules cohere to each other (bc polar)
molecules bonded to walls of tube (adhesion) (when 1 molecule leaves through stomate another is pulled up into its place–sun=driving force in pulling water molecules up)
mass/pressure flow theory
xylem/phloem tubes run up plant
sugar pumped in at top of phloem tube by ATP and water follows
sugar pumped out at bottom of phloem tube by ATP (to be stored in root) and water follows
high pressure at top of phloem tube
low pressure at bottom of phloem tube
aphids
drink sugar water from phloem
can’t stop drinking when full so sugar water comes out their back side
sap collection
spicket drilled into XYLEM of sugar maple tree
sap rising up xylem and drawn off into bucket when it hits the spicket
CO2
often limiting factor for plant growth CAM plants (succulents): adapted for stomates to open at night --> less water stress and more CO2 enters and is stored (CO2 used for photosynthesis)
what effects stomates
open and close effected by H2O availability and blue light
blue light
opens stomates starting at dawn
triggers release of K+ across membrane going inward and water follows
effect of increased temp on stomates
closes stomates
increased cell respiration and CO2 production
types of cell growth and development
- cell division (apical meristem actively dividing)
- cell growth (elongation)
- cell differentiation/specialization
- production of hormones
hormones
produced at everyday plant parts
no separate glands–no endocrine system
sometimes inhibitory at 1 concentration and catalyze at another concentration
5 main hormones
auxins cytokinins ethylene abscisic acid gibberellins
auxins
effects studied by Darwin
- phototropism
- cell differentiation
- promotion of fruit growth
- apical dominance
- prevent abscission
- weed control
phototropism
indole acetic acid moves down xylem
at some point it starts moving sideways to dark side which stimulates differential elongation on light side which turns everything to grow towards light
cell differentiation
- auxins in leaf primordia (auxins move down and make cells turn into vascular tissue (xylem and phloem))
- auxins in terminal bud (when bud bursts auxins are produced and ooze down short distance to make vascular cambium produce big vessel elements to carry more sugar water up
- artificial auxins (promote root growth)
promotion of fruit growth
young fertilized ovule produces auxin which stimulates ovary to become fruit which protects seed
spray unfertilized flower with auxins to produce seedless fruit
apical dominance
auxins keep lateral buds from producing competing branches
has lesser effect farther you get from terminal bud
if you cut off terminal bud all lateral buds will grow (why we prune shrubs)
prevent abcission
auxins prevent abscission zone from forming
apple orchards spray trees with auxins so apples don’t fall on ground and instead stay until ready to be picked all at once
weed control
auxins delivered at toxic levels
only targets dicots (doesn’t effect grass)
became big during Vietnam war (sprayed in forests to see enemies)
cytokinins
don’t act alone–act with something else sometimes auxins (RATIO MATTERS)
1. promote cytokinesis (stimulate cell division)
found in actively dividing areas of plants
2. promote lateral buds
3. prevent leaf senescence (leaf aging)–keep chlorophyll going longer
ethylene (gas)
- promotes fruit development
- promotes abscission
- promotes femaleness in cucurbits (squash)
- promote stem thickening
- aerenchyma tissue
promotes fruit development (ethylene)
tomatoes shipped green then gassed with ethylene to quickly ripen before putting out at store to sell
if 1 tomato in box is overripe all others will ripen bc it will produce enough ethylene to ripen others as well
promotes abscission
citrus growth–lightly spray grapefruit trees so some fall off premature and branch doesn’t break
(work against auxins)
promotes femaleness in cucurbits
cucurbits grow on monoecious vines
early in season have all male flowers
spray some male flowers with ethylene to turn them female and get fruit sooner
promote stem thickening
ethylene produced in stress response
makes stem stronger to pull cotyledons above ground when covered in pebbles
thicken trunk of pine tree on edge of cliff to protect from wind
aerenchyma tissue
oxygen stress –> ethylene formation –> formation of cellulase (breaks down cellulose–what cells are made of)
tropisms
phototropism
gravitropism/geotropism
thigmotropism
gravitropism/geotropism (C-)
roots grow down (positive geotropism)
stem grows up (negative geotropism)
statoliths involved in this
statoliths
auxins attach to these
they drop to the bottom and stimulate cells on bottom to elongate making them grow up (stems)
don’t know why roots grow down though
thigmotropism
tendrils reach up and wrap around support structure
when back side touches cells elongate and wrap up around structure
phytochrome mediated response
used to detect if in light/not in light P(red) P(far red) red=inactive far red=active when it experiences red light it goes to far red (vice versa) red --> far red = day conversion far red --> red = night conversion 1. seed germination 2. etiolation 3. phototropism 4. photoperiodism
phytochrome seed germination
some seeds have to be in light to germinate (weed seeds)
why we cover weeds with mulch
etiolation
taller and thinner than normal stems due to plant seeking light
can undergo de-etiolation response to green up
photoperiodism
flowering response
use this to determine what time of year it is by amount of sunlight during day
some plants on a flowering schedule (every 16 hours)
1. long day (summer)
2. short day (late fall, winter, early spring)
florigen
could possibly carry phytochrome to bud which triggers it to turn into a flower
temperature mediated response
let seeds sit out in winter they will freeze and thaw repeatedly which will give around 100% germination
stratification
scarification
vernalization
stratification
in big pot put layers of sand then seed then sand then seed…
scarification
put seeds in giant tumbler to weaken seed coat/create scars which will promote germination
vernalization
need for certain number of hours of cold for maximum bloom and fruit
peaches need cold but can’t withstand late freezes
circadian rhythms
24 hour cycles
plants reset themselves every 24 hours due to temperature and light
things affected by circadian rhythm
flower opening and closing auxin production mitosis root pressure discharge of fungal spores
flower opening and closing
schedule adapted to accommodate pollinators
auxin production
schedule of when elongation events take place
mitosis
different plants have different times of cell elongation
root pressure
higher root pressure at dawn
discharge of fungal spores
dispersed early in morning so they catch a light breeze and travel a short distance
4 external factors
tropisms
phytochrome
temperature mediated response
circadian rhythm
abscisic acid
plant tranquilizer (inhibitor-works against other hormones)
- promotes dormancy
- promotes leaf and fruit abscission
- transpiration
ABA promotes dormancy
after winter ABA destroyed by all the freezes and thaws throughout season
terminal bud and acorn
ABA promotes leaf and fruit abscission
works against auxins and with ethylene
ABA transpiration
collection of water leads to collection of ABA which closes stomates and prevents transpiration
gibberellins
1st gibberellin isolated from fungus on rice plant that made them fall over
- promote cell division and elongation
- promote production of parthenocarpic fruits
- promote seed and pollen germination
gibberellins promote cell division and elongation
do job of cytokinins and auxins
(dwarf mutants lacked production of gibberellins so spray to make stem grow)
useful to stretch things out
gibberellins promote production of parthenocarpic fruits
promote production of seedless fruits
make seedless grapes and elongate them to make them bigger to sell
chlorosis
spotted yellow on leaves
necrosis
spots of dead tissue
monocot # of petals
3’s
dicot # of petals
2, 4, or 5
connation
fusion within whorl (petals fused to petals)
adnation
fusion between whorls (stamen fused to petal)
endosperm
triploid
embryo
diploid
ovary becomes
fruit
