Bio test 2

kingdom plantae

primarily angiosperms, flowers and fruits, seeds are the best, vascular tissues (best)

seeds

reproductive structures produced by angiosperms and other seed plants, result of sexual reproduction, contain embryos that develop into seedlings, store food, 2 seed coats protect embryo, vessel- enclosed in fruit

alternation of generations

exhibited by all plants, alternate between diploid plant form (sporophyte) and a haploid plant form (gametophyte)

gametophyte

gamete producing plant form, multicellular, microscopic in flowers, grow and develop in flowers, produces gametes by mitosis (no change in number), haploid

sporophyte

spore producing by meiosis, multicellular, large plant in flowering plants, produce haploid, reduce number

syngamy

fertilization, results in formation of diploid zygote that undergoes mitosis to form a multicellular embryo

plant embryo

a sporophyte (early) that lies dormant in the seed with supply of stored food and seed coats, might lay dormant for long period until the conditions are favorable

shoot system

stem- produce leaves and branches, have reproductive structures

leaves- flat structures designed for photosynthesis

root system

roots- provide anchorage in the soil, storage of food and water and uptake of water and minerals

growth

inderminate growth- increase in size as long as its alive, grows into a seedling and mature plant, occurs in 3 ways

what 3 ways does growth occur

increase in cell number through mitosis, increase in cell size, increase in weight

development

mature plant produce reproductive structures (flowers, seeds, fruits), flowers and floral buds are reproductive shoots that develop when shoot apical meristem (tips) produce flower parts instead of new stem or leaves, flowers produced by determinate growth, flower tissues close and protect tiny male and female gametophytes, fruits enclose seeds and function in seed dispersal and protection

meristems

seedlings and mature plants produce new tissue from this, “cell factory”, region of undiffertiated cells that produce more, dormant occur at shoot and root tips of seed embryos (activate in seedlings), mature plants have shoot and root apical meristem at tips, older cells become specialized

hierarchy of structure

specialized cells →tissues →organs →organ system (branches, buds, flowers) →root and shoot system →plant (organism) sporophyte

primary growth

elongation of plant organs, roots and stems and leaves, all plants have this, produces primary tissues from RAM and SAM, when embryo breaks from seed its a root

primary tissues

primary xylem, primary phloem epidermis, parenchyma, collenchyma, sclernchyma

primary xylem

vascular, water and minerals

primary phloem

vascular, food and solute

epidermis

1 cell thick, protect, outermost tissue

parenchyma

most abundant, storage, part of cortex/pith

collenchyma

protect and support the growing plant organs, cortex, thick

sclerenchyma

support of non elongating organs, cortex, thick

secondary growth

expansion (diameter) of plant organs (lateral meristems), results in increased diameter of plant organs, roots and stems only, not all plants have this, produce secondary or woody tissues

what part of plants experience secondary growth

roots and stems but not leaves

root system adaptations

major functions: absorb water and minerals, anchor plant in soil, store nutrients and water

what are the 3 zones of root growth

region of cell division, region of elongation, region of maturation

region of cell division

RAM and root cap, RAM has constantly dividing cells, root tips have lubricating mucigel

region of elongation

cells extend by water uptake

region of maturation

root cell differentiaion and tissues specialize into primary tissues, idntify root hairs absesnt from older regions

root internal structure

epidermis: encloses a cylinder of parenchyma called cortex and rich in stach with intercellular air spaces

endodermis: inner layer of cortex and selective absorbtion of water and minerals and is surrounded by a layer of waxy tissue

merisytematic pericycle encloses root vascular tissue to produce lateral roots

woody roots primary vascular then secondary growth

what 4 parts make up shoots

stem node- leaves emerge or branches

internode- stem between adjacent nodes

leaf- absorb sun for photosynthesis

axillary meristem- generate axillary (lateral) buds that will produce flowers or branches and new branches will have SAM tips

terminal bud

at end of shoot has SAM and other parts

Leaf adaptations

eudicots have net venation- lots of branching and provide more support, monocot have parallel venation, more surface area means more photosynthesis/mesoderm

eudicot stems

primary (elongate) and secondary (expand) in most vascular bundles form ringed pattern and exhibit both pith and cortex

monocot stems

primary growth (elongate) and lack both pith and cortex becuase of vascular tissue and are scattered in cells

lateral meristems

secondary tissues, rings that retain cell division properties and produce “rings” of secondary tissues to the cambium rings, expansion

vascular cambium

produces ring of secondary xylem to inside and secondary phloem to outside

cork cambium

produces rings of periderm (outer bark) that replaces epidermis and cortex for external protection

secondary growth in eudicot stems

begins late in the the 1st year of growth, only left from primary is the pith and pieces of primary xylem, 3 rings of secondary xylem (adds every year)

comparing leaves

monocot- parallel venation

eudicot- net venation

primary growth only

comparing roots

eudicots- primary and most have secondary growth, cortex and no pith because of a core of xylem in the center, tap root

monocots- primary growth only, cortex and pith with xylem and phloem, fibrous root system

contain endodermis and pericycle

comparing stems

eudicots- primary and most secondary growth, vascular bundles in ‘ring’ forming pith and cortex

monocots- primary growth only, vascular bundles scattered, no pith and no cortex

do all plants have primary growth

yes!

hormones

chemical messengers that regulate plant growth, most transported in phloem tissues that requires ATP, need water and ATP and ideal environment, interactive with external environmental factors to determine growth

what all do hormones control

growth, seed germination, flowering, fruiting/seed production, shedding leaves, changing leaf color

growth inhibitors (hormone)

mostly in fall and winter, certain time of year growth is not good

growth promoter (hormone)

mostly in spring or summer and promotes growth

auxins

first group of plant hormones described, growth promoter; found in: shoot tips, embryo seeds, fruit, leaves, stems; effects: promote cell elongation, promote wood production, inhibit lateral bud development, promote shoot elongation, promote fruit development, inhibit abscission of leaves and flowers and fruits

cytokins

originally found in coconut milk, growth promoter; found in: seeds, fruits, roots; effects: promote cell division, inhibit leaf color changing, promote lateral bud development; chlorophyll a is primary

gibberellins

many types, growth promoter, found throughout the plant but concentrated in seeds; effects: promote stem elongation by stimulating cell division, promote breakdown of food reserve in germinating seeds

what directs the time of germination

embryo

process of secreting gibberellins

intake of water causes swelling and embryo hydrated, embryo secretes gibberellins, gibberellins transported to cells of a leurone layer to secrete enzyme for breakdown of endosperm to glucose, enzyme with respiration glucose to produce ATP

brassinostaroids

growth promoter, effects: promote cell expansion, promote shoot elongation, promote xylem tissue development, promote stress response, inhibits leaf abscission

abscisic acid

growth inhibitor, found in: seeds, mature leafs, dormant buds (mainly); effects: inhibit cell elongation, promote leaf senescence, inhibit alpha amalyse production, promote storing carbohydrate production in seeds

ethylene

growth inhibitor, a gas produces by incomplete break and metabolism, not transported through phloem, effects: promote fruit ripining, promote abscission of leaves fruits and flowers, interact with four growth promoting hormones to determine cell size and shape

seed germination

requires breaking of dormancy, internal: hormones and stored food with water absorbed and embryo swelling, external: sunlight and soil/air temperature with longer days and moist soil

seedling

result of cell reproduction and increase in cell size, internal development: cell→tissue→ organ→ organism, radicle is the 1st to emerge and 1st root and will grow down

what nutrients does photosynthesis require

CO2, water, potassium, nitrogen, and calcium

macronutrients

required in amounts of at least 1g/kg of plant dry mass

micronutrients

trace elements, require in amounts at or less than 0.1g/kg of plant dry mass

what are the nutrient limiting factors

resources that can limit growth such as: light, CO2, water, other mineral nutrients

essential elements

16 essential elements like carbon, hydrogen, and oxygen; absorbed and dissolved in water through roots, 13 is xylem, all plants have to have these

nitrogen

components of protein, nucleic acid, chlorophyll; macronutrient

potassium

involved with osmosis and ion balance, opening and closing of leaf stomata (loss of water vapor from leaves); macronutrient

phosphorous

phosphoric backbone, component of nucleic acids, ATP, phospholipids of plasma membrane; macronutrient

calcium

component of cell wall (cellulose); macronutrient

sulfur

component of proteins and 10 enzymes; macronutrient

magnesium

component of chlorophyll, enzyme activator; macronutrient

molybdenum

enzyme co factor, micronutrients

manganese

enzyme co factor, involved with cholorplast, membrane and for O2 release with photosynthesis; micronutrient

copper

enzyme co factor; micronutrient

zinc

enzyme co factor; micronutrient

chlorine

splits water molecules in photosynthesis, ion balance; micronutrient

boron

really minor, enzyme cofactor, cell wall component, nucleic acid synthesis; micronutrient

iron

enzyme cofactor, componenet of cytochromes, needed for synthesis of chlorophyll; micronutrient

importance of water

photosynthesis, support for plant organs, average cell has 90% water, flows throughout plant, need proper amount for cell elongation, most chemical reactions need water to start, solvent for most substances

properties of water

polar molecule- neutral, hydrogen bonding tight links to four others, cohesiveness “net”, adhesiveness so stick to other polar compounds, temperature stabilization, transport medium so flows and whats in it flows with it, best biological solvent and wont kill the solute, occurs in all 3 forms with in earths temperature range

purely physical process

no atp is expended in movement

bulk/mass flow

mass movement of liquid caused by pressure, gravity, or both; faster than diffusion; movement of ions through soil to plant roots

simple diffusion

movement of molecules through a phopholipid bilayer down a concentration gradient

fascillitated diffusion

transport of molecules across plasma membrane down a concentration gradient

osmosis

diffusion of water across a selectively permeable membrane in response to differences in solute concentrations

aquaporins

protein channels allow for facillitated diffusion of water

turgid

cell has cytosol full of water and plasma membrane presses against cell wall, more rigid and supportive

plasmolyzed

lost so much water that turgor pressure is lost and plasma membrane no longer presses on cell wall

transpiration

evaporation of water from plant surfaces; “cost” of living on land, capable of pulling water up by bulk flow, primary form of long distance water transport

what indirectly powers transpiration

sunlight energy because its heat causes change of water from liquid to vapor

xylem

flowering plants have the best, parenchyma cells are alive, thick walled supportive fibers maybe alive or dead at maturity, tracheid and vessel elements are specialized water conducting cells and are always dead and empty of cytosol when mature

tracherery elements

rich in lignin, which confers strength and durability and water proof, cluster together

stomata

plants produce waxy cuticle to prevent water loss but not over this, facillitates gas exchange, 90% of water that evaportates is lost through this, when open O2 and water are released and CO2 is taken up

mechanism for guard cells

daytime/sunlight when CO2 is low in the leaf, will pump in potassium and change solute concentration and use ATP, water from xylem moves by osmosis into this, these will swell and open the stoma, then pump out potassium and water moves by osmosis out of the cell causing them to shrink and lose ATP, depends on water in soil, plant and atmosphere

cause of water loss

sunlight energy heats up leaf causing evaporation of water from mesophyll cells, causes a decrease in water concentration aka a ‘pull’ of water which moves water through the transpiration stream

transpiration stream

soil nutrient →root epidermis→root cortex→ endodermis→ vascular cylinder

root xylem→stem xylem→leaf xylem→mesophyll →heated vapor into atmosphere through stomata

“pull” tension throughout plant

CAT mechanism

unidirectional, once stomata open and purely physical process, pull of one water molecule at a time, no energy expended only energy is sunlight heating leaf, C- cohesion: water molecules stick together with hydrogen bonds, A-adhesion: water adheres to cellulose in walls, T-tension: pull due to water loss from mesophyll

translocation

movement of solutes in plants

similarities between transpiration and translocation

involve conduction, involve physical properties of water

differences between transpiration and translocation

translocation: phloem and bidirectional, expend ATP, energy by plant

transpiration: xylem and unidirectional, sunlight energy, not by plant

long distance transport in phloem

transport sugar from where produced to other sites where used or needed, primary occurs in vascular bundles of herbaceous plants, secondary occurs at inner bark of woody plants

phloem structure

flowering plants: supporting fibers, parenchyma fibers, sieve tube elements, adjacent companion cells

sieve tube members

arranged end to end and together with companion cells to form a system to transport soluble organic substances, loses its nuclesus and most of cytoplasm to reduce obstruction of the flow, phloem sap passes through sieve plate pores