Exam 1 - BIOL 1106
etiolation
pale yellow color, thin, weak -caused by lack of red light
symplast route
strict transport through plasmodesmata
phloem translocation: loading
sucrose enters phloem via active transport, sucrose and water removed at sink via osmosis -continues through phloem to sinks via passive transport
phytoaccumulation
the plants takes in contaminant and stores it in shoots plant is removed and typically destroyed
phototropin II associated with
Golgi Apparatus
Vascular tissue
Xylem & Phloem moves water and nutrients against gravity
Are cations or anions more readily available to plants?
anions
____ in solution create a graident causing protons to exit root (using active transport)
anions
meristems that aid in root and shoot extensions
apical -located at tips of stems and roots -give rise to primary tissue -root cap - protects root apical meristem -leaf primoridia- protects shoot apical meristem
waters intermembrane channels
aquaporins -enhances osmosis across membrane (moves water fast) -doesnt change direction
"sun-shy hormone"
auxin - produced in shoot tip apical meristem
what hormone is a gas?
ethylene
"ripening hormone"
ethylene -gaseous -surppresses stem elongation
In shoot gravitropism _____ have increased auxin concentration on the lower side which causes that area to grow more than the cells on the upper side resulting in bending.
horizontal stems
Abscission
protective and seperation layer
Advantages of the seed?
protects embryo from desiccation -acts as food supply increased dispersal range -pollen grain
water and mineral absorption
root hairs -rot pressure moves water up the xylem
Even in the absence of transcription, some water can move into the roots and partially up the xylem columns. This phenomenon is due to
root pressure
two groups of seed plants?
angiosperms gymnosperm
P(r)
absorbs red light -found in cytoplasm -sunlight chnges Pr - Pfr
transpiration
"the pulling force" movement of water through a plant and its evaporation from leaves
roots
"the pushing force" caused by water entering roots but water moves against gravity via xylem
Soil characteristics
-highly weathered outer layer -composed of sand, rocks, silt, clay, humus, minerals -full of microorgansims that are important in soil breakdown
soil micronutrients
Cl, Fe, Mn, Zn, B, Cu, Mo
gravitropism
directional growth based on gravitation field of earth
What cells lack living protoplasts at maturity?
sclerenchyma
main component of wood
secondary xylem
allelopahtic plants secrete chemicals to block ______ or inhibit ___ of nearby plants
seed germination; growth
defensins
small, cyteine-rich peptides w/ antimicrobial properties some can limit protein synthesis
pressure flow hypothesis
source -> sink phloem translocation: loading
source to sink
source = photosynthetic levels sink = growing stems, root tips, and fruits
phytodegredation
the plant breaks down the contaminant into other components
phytovolatilzation
the plant take in the pollutant and releases it through stoma
Bryophytes
-nonvascular (not tracheophyte), seedless, flowerless plant -lack a true root system (rhizoids absorb the small amount of water) -repro aided by water -gametetophyte dominant -closest living decendants of first land plants
dormany induced by increases in ____
ABA
soil macronutrients
C, H, O, N, K, Ca, Mg, P, S
Phytochrome-red enters the plant cell nucleus and regulates gene expression.
False
Tracheophytes
First vascular plants -true roots, waxy cuticle, stomata
"Alterations of Generations"
Haplodiplontic cycle Diploid = sporophyte Haploid = gametophyte
mineral and organic soil particles tend to have ____ charges, so they attract ____ charged molecules and ions. The charge gradient produced in the soil solution causes ___ charges to tend to move out of the root hairs.
Negative; positive; positive
The ____ hypthesis explains the translocation of carbohydrates in the phloem tissue.
Pressure-flow
You can determine the age of an oak tree by counting the annual rings of ____ formed by the _____.
Secondary xylem; vascular cambium
P(fr)
absorbs far red light (active -binds to proteins that form transcription complex -expression via protein kinase-signaling pathways
Water molecules can "stick" to other surfaces by
adhesion
gravity sensing mechanism called
amyloplasts
Long day plants require ____ to trigger a flowering response
an uninterrupted dark period that is less than the critical length for that species
Enclosed seeds
angiosperms
rhizobia (not to get confused with rhizoids)
bacteria that fix atmospheric N2 into nitrate for plants
"steroid wannabe"
brassinosteroids -effects most everything in growth
Which plant group has a dominant gametophye generation?
bryophytes
positive potential
caused by water entering roots
pulvini
cell clusters at leaf base that change turgor pressure
zone of maturation
cells specialize into xylem, phloem, etc.
turgor is most directly related to the plant cells'
central vacuoles and cell walls *
phototropin I has two light sensing regions that ________ b/c blue light. stimulates ____ --> signal transduction
change conformation; autophosporylation
"sister group" to all land plants?
charophytes
Which of the following would not be considered a macronutrient for plants?
chlorine
meristems
clumps of cells with dense cytoplasm and large nuclei that undergo mitosis -indefinite mitotic divisions --cells begin to differntiate *think stem cells*
produces outer bark
cork cambium
Which of the following chemical defenses is common to plants and animal and provides antimicrobial activity?
defensins
phototropism
directional growth based on light (blue light photoreceptors) -auxin present on particular side of plant causes growth
thigmotropism
directional growth in response to physical contact
if plant lacks R gene or an avr gene, then
disease occurs
cytokinin stimulates cell ____ and _____. Produced in the____ and promotes growth of ______ on branches.
division; differentiation; root tip; lateral buds (inhibits lateral root formation)
seed germination is inhibited by _____ and stimulated by ____. germinates when in direct ____sunlight
far red light; red light; direct
Which innovation likely contributed to the tremendous success of angiosperms?
fruits that enhance dispersal
Guard cells/ stomata (dermal tissue)
gas exchange and water diffusion
"growing buddy hormone"
gibberellins -promotes germinations w/ auxin -enhances stem elongation
The leaf mesophyll is composed of parenchyma cells and makes up the ____ tissue of the leaf.
ground
primary meristem that forms ground tissue
ground meristem
Parenchyma, collenchyma, and sclerenchyma are all types of cells in the...
ground tissue
storage, photosynthesis, and secretion layer of tissue
ground tissue
____ regulate the opening and closing of the stomata
guard cells
Which term means "nakes seed?"
gymnosperm
"naked seed"
gymnosperms -ovule (unfertilized seed) exposed -lacks fruits&flowers to cover ovule
root hairs (dermal tissue)
increase surface area for water and mineral absorption
meristems that increase girth of systems
lateral -found in plant exhibiting secondary growth -woody plants have two types
flower development pathways
light, temperature, gibberellin-dependent, and autonomous
zone of cell division
location of apical meristem, cells grown prior to specialization
Reproductive strategies of angiosperms
male gametophyte -pollen grains contain 2 sperm Female gametophyte -egg & polar nuclei Double fertilization
pollen
male gametophyte containing sperm
which process produces haploid spores during alternation of generations?
meisosis
transmembrane route
membrane transport between cells and across membranes of vacuoles within cells -permits greatest control
What provides nutrients, protects against invasion of foreign pathogens for the plant?
microrrhizae (fungi) symbiotic relationship
ground tissue- parenchyma
most abundant -thin walls, large vacuoles, many chloroplasts -alive at maturity
although symbiotic relations between nitrogen-fixing bacteria and plants are rare, many plants have symbiotic relationships with
mycorrhizal fungi in the soil
soil particles that are ______ attract cations in solution that are _____
negative; positive
if plant has R gene that recognizes the avr gene, then
no disease
photomorphogenesis
nondirectional, light-triggered development -seed germination, flower development, stem elongation
immunity initiator
oligiosaccharins
double fertilization
one sperm fuses with egg to form zygote (diploid) one sperm fuses with polar nuclei to form endosperm (triploid)
Dermal tissue
outer, protective layer of tissue (forms epidermis) -covered in fatty cutin layer -contains special cells
the wounded leaf produce small ___ called ___. systemin moves through the plant ____ into ____. Once it reaches an appropriate membrane-bound receptor, it initiates the production of _____. JA in turn elicits ____ for the transcription of a proteinase inhibitor
peptide, systemin; apoplastically, phloem; jasmonic acid (JA); gene expression
What is not a plant characteristic that is an adaption for a terrestrial environment?
photosynthesis
2 components of water potential
physical forces- turgor pressure solute concentration
plants can remove harmful chemicals from the soil by the process of:
phytoremediation
phytochrome
pigment molecule
gene-for-gene hypothesis
plants have a resistance gene (R) pathogens have avirulence gene (avr)
auxin increases the _____ of cell walls and is involved in _____
plasticity; stem elongation
water potential
predicts movement of water -moves from high to low -megapascals
primary meristem that produces primary vascular tissue
procambrium
Root cap
protect apical meristem, cell continually replace, secrete slime
primary meristem that forms epidermis
protoderm
____ in the solution cause soil to release cations. cations are then taken in by _____
protons; root hairs
shoot elongation has normal growth and color in _____ light
red
Trichomes (dermal tissue)
reduce evaporation, protect from harsh light, can secrete toxins
zone of elongation
root elongates as vacuoles enlarge
Most of the water that evaporates from leaves passes out through the
stomata
apoplast route
strict transport through cell walls and space between cells -can be blocked by casparian strip
Desiccation
tendency to lose water to the air Overcome this by covering its cuticle
Cation Exchange Capacity (CEC)
the capacity of a soil to attract/hold positively charged ions
ground tissue- collenchyma
thick walls, provide flexibility and support -alive at maturity
ground tissue- sclernchyma
thick walls, secondary walls contain lignin -dead at matruity
cuticle
thick, protective coating that limits gas exhange
which plant growth response does not involve phytochrome?
thigmotropism
____ transportation routes
three
negative potential
top of plant; due to transpiration or water loss
the hypersensitive response (local)
triggered by invasion of pathogen and appropriate R gene -plant begins to cause local cell death around site -sudden apoptic signals are generated (NO and H2O2) -seals off pathogen to that site
the wound response
triggered by mechanical wounds from chewing or injury
systemic acquired resistance (broad-range)
triggered by second invasion of pathogen -signaling molecule initiaes SAR -enables the plant to respnd quicker -uses salicylic acid and JA
Vascular tissue: Phloem
two types: sieve cells- seedless, vascular, gymnosperms sieve tube members -angiosperms
phytoremdiation
use of plants to concentrate or breakdown pollutants (3 processes)
produces secondary vascular tissue
vascular cambium
conduct fluids, nutrients, and hormones
vascular tissue
Vascular tissue: Xylem
vessels- large diameter hollow tube w/ perforation plate tracheids- small diameter hollow tubes w/ pits
total water potential
water moves from high concentration to low concentration