APBIO CH. 36,38, 39

145 terms by JuliusTembe

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Guttation

The exudation of water droplets, caused by root pressure(an upward push of xylem sap) in certain plants. Usually is very minor in a plant and can only force water up a few meters. (NOT the same as DEW)

Zea Mays

Varieties of corn evolved from Teosinte. Originates in Mesoamerica and is a prominent staple in the diet of New World cultures

Wilting

The dropping of leaves and stems as a result of cells becoming flaccid.

Monoecious

A plant in which the staminate and pistillate flowers are separate, but borne on the same individual.(Maize)

Ethylene

The only gaseous plant hormone, responsible for fruit ripening, growth inhibition, leaf abscission, and aging.(), can lead to programmed cell death(Apoptosis),; Leaf abscission, and fruit ripening. C2H4

Detiolation

Informally known as greening, this occurs when a plant shoot reaches the sunlight. In this process the elongation of the stem slows, leaves expand, roots elongate, and the shoot produces chlorophyll.

Dioecious

Referring to a plant species that has staminate and (Arrowhead)carpellate flowers on separate plants.

Sporophyte

The multicellular diploid form in organisms undergoing alternation of generations that results from a union of gametes and that meiotically and produces haploid spores that grow into the gametophyte generation.

Gametophyte

The multicellular haploid form in organisms undergoing alternation of generations that mitotically produces haploid gametes that unite and grow into the sporophyte generation.

Endosperm

A nutrient-rich tissue formed by the union of a sperm cell with two polar nuclei during double fertilization, which provides nourishment to the developing embryo in angiosperm seeds.

Spores

single-celled reproductive bodies highly resistant to cold and heat damage; capable of new organisms

Stomata

The small openings on the undersides of most leaves through which oxygen and carbon dioxide can move. Leads to a maze of internal airspaces that expose mesophyll cells to CO2 they need for photosynthesis

Passive Transport

Diffusion of solutes down their gradients and across a membrane, does NOT require energy.

Active Transport

Pumping of solutes across a membrane against the electrochemical gradient, requires energy usually in the form of energy.

Electrochemical Gradient

The combined effects of the concentration gradient of solute and the voltage.

Voltage

Charge difference

Transport Proteins

Proteins embedded in the phosopholipid bilayer of the plasma membrane of a cell. Some bind selectively to a solute on one side of the membrane and release the solute on the opposite side. Others provide selective channels across the membrane. For Example: (K+) (Na-) channel.

Proton Pump

Most important active transport protein in the plasma membrane of plant cells. Uses energy from ATP to pump hydrogen ions(H+) out of cell creating a proton gradient with a higher (H+) concentration out of the cell than inside. In contrasqt to ATP synthases they run in reverse.

Potential Energy

The form of energy that the proton graident is. Occurs because hydrogen ions tend to diffuse"downhill" back into the cell, and this flow of H+ can be harnessed to do work, also contributes to voltage known as membrane potential

Membrane Potential

A separation of opposite charges across a membrane created by the pumping out of H+ ions out of a cell. Makes the inside of a cell negative and outer more positive. Also a form of potential energy. Contributes to the uptake of K+ ions by root cells.

Cotransport

Mechanism in which a transport protein couples the downhill passage of one solute to the uphill passage of another. In plants it is responsible for the uptake of sucrose by plant cells. Happens when membrane protein cotransports sucrose with the H+ that is moving down its gradient through the protein.

Chemiosmosis

Process involving a trans-membrane proton gradient, which links energy releasing process to energy consuming processes in cells.

Osmosis

The passive transport of water across a membrane.

Water Potential

Represented by Greek letter psi (ψ). Is the combined effects of solute concentration and physical pressure. Determines the direction of movement of water. However water that is not bound to solutes moves from regions of higher water potential to regions of lower water potential.

Megapascals

Abreviated (MPa). Are the units in which water potential(ψ) are measured in. Pure Water = 0 MPa. 1 MPa = approximately 10 Atmospheres.

Pure Water

Has a water potential of 0 MPa when in a container open to atmosphere under standard temperature and pressure.

Atmosphere

Pressure exerted by an imaginary column extending through the entire height of the atmosphere.

Water Potential Equation

ψ= ψS + ψP. ψ = water potential, ψS = solute potential(osmotic potential) and ψP = pressure potential.

Osmotic Potential

Also called the solute potential because solutes affect the direction of osmosis. Adding solutes always lowers water potential because solutes bind to water molecules reducinf the number of free water molecules and lowering the capacity of the water to do work.

Pressure Potential

The physical pressure on a solution. Can be positive or negative. Air in a ballon and the water in living cells would be under positive pressure, while water in dead cells(like xylem would be under negative pressure.

Turgor Pressure

The pressure produced when the cell contents press the plasma membrane against the cell wall.

Flaccid

limp, not firm; lacking vigor or effectiveness, when this type of cell is put in a solution of higher solute concentration( more negative solution potential) , water will leave the cell by osmosis and the cell walls protoplast will plazomolyze. However if this type pf cell is placed in pure water (lower water potential) then water will enter this cell producing a turgor pressure.

Plasmolyze

To shrink and pull away from a cell wall, or when a plant cell protoplast pulls away from the cell wall as a result of water loss.

Aquaporins

Channel proteins that ficilitate the passage of water molecules through biological membranes, does not effect gradient or direction, but the RATE at which water diffuses down its water potential gradient.

Tonoplast

Also known as the vacuolar membrane. Regulates molecular traffic betwen the CYTOSOL and the VACUOLAR contents(cell sap), its protein pump expels H+ from cytosol into the vacoule, which is then used to move other ions across the vacuolar membrane by chemiosmosis.

Plasmodesmata

Open channels in the cell wall of a plant through which strands of cytosol connect from an adjacent cell. Forms a continuous pathway for transport of certain molecules between cells.

Apoplast

The continuum of cell walls connected by plasmodesmata plus extracellular spaces.

Cytosol

The part of the cytoplasm that includes molecules and small particles, such as ribosomes, but NOT the membrane bound organelles. Located WITHIN the plasma membrane but outside intracellular organelles.

Symplast

In plants, the continuum of cytoplasm connected by plasmodesmata between cells. Do NOT confuse with the Apoplast ( which is this plus extracellular)

Lateral Transport

Short distance transport that is usually along the radial axis of plants(Rather than up and down). Used by root hairs to transport water and minerals to vascular cylinder in the root.(3 different routes). In the tranmembrane route a substance moves out a cell across the cell wall into the next cell, which continues to move in the same way for each cell. The symplast route requires crossing just 1 plasma membrane, and then the substance can move cell to cell by plasmodesmata. The apoplast route does not require using a protoplast and movement of water and solutes occurs along the byways provided by continuim of cells.

Bulk Flow

Long distance transport driven by pressure. In this water and solutes move through the trachieds, vessels of the xylem, and through the sieve tubes of the phloem(high positive pressure forces substances to diffuse to other side. In xylem it is tension(negative pressure) that drives long distance transport(by pushing xylem sap through the roots). Volume of flow in container is also determined by internal diameter.

Water flow from Soil

Passes through EPIDERMIS, then ROOT CORTEX, Vascular Cylinder, and then flow up tracheids and vessels to the shoot system.

Root Tips

Place where much of the water absorption occurs, its where the epidermis is permeable to water and where root hairs are located.

Root Hairs

Extensions of epidermal cells which help increase the surface area of the root and bring in more water and nutrients.

Endodermis

The innermost layer of cells in the root cortex which surrounds the vascular cylinder and functions as the last checkpoint for the selective passage of minerals from the cortex into the vascular tissue.

Casparian Strip

Found in the transverse and radial belts of every Endodermal cell. Is made of Suberin making it impervious to water and dissolved minerals, forces water to enter vascular tissue via the apoplast ,and insures no minerals can reach vascular tissue without being selectively screened

Transpiration

The loss of water vapor from leaves and other aerial parts of the plants.

Embolisms

Blockages of the water cavities of the xylem. Rapid expansion of this produces clicking noises that can be heard by placing sensitive microphones at the stem.

Parenchyma Cells

Most abundant, un-specialized, with only primary walls that are thin and flexible. Function: food storage, photosynthesis, aerobic respiration. Can differentiate into any other plant cell type. Make internal surface area of a leaf 10 to 30 times the surface area on the external leaf. (Found in Stomata(Structure Fits function)

Etiolation

Morphological adaptations for growing in the darkness, found in potatoes mainly sprouting from their auxillary buds.

Tuber

A modified stem(think Potato)

Phytochrome

A photoreceptor that is also found in the detiolation process. Occurs in the cytoplasm unlike most receptors which are found in the plasma membrane

Aurea

A type of "gold" tomato has lower than normal levels of chlorophyll that scientist study in order to demonstrate the plants requirement for phytochrome, is a close relative of potato

Second Messengers

Small, internally produced chemicals that transfer and amplify the signal from the receptor to other proteins that cause the response.

Ca2(+)

This along with cylic GMP increases when a conformational change caused by light attatching to phyochrome. Are second messengers. This can increase to 100 times its level with phtochrome.

cylic GMP

Can lead to ionic changes within ion channels and can also activate protein kinases(Phosphoralaytiion which influeces other enzymes)`

Transcriptional Regulation

This involves stimulating transcription of mRNA for the enzyme. Some require Ca and others cGMP. Think Arabdopsis mutants.

Auxin

One in a class of plant hormones that stimulates (among other things) cell elongation, secondary tissue growth, and fruit development, also make stem length decrease. In detiolation. Together with brassinosteriods. Was purified by Kenneth Thimann and was determined to be indoleactic acid(IAA). transported from the SHOOT APEX at about 10mm/hour, directly or Parenchyma tissue, and only moves from shoot to base(Polar Transport)

Hormones

Chemical signals that coordinate the growth of organisms, produced by one part of the body then transported to another. Even small amounts can produce tremendous changes in the organisms.

Tropism

A growth response of a plant toward or away from a stimulus

Positive Phototropism

Growth of a shoot towards light. Mainly known from gras seddlings(oats)

Coleoptile

A sheath that a shoot of a sprouting grass would be in. Charles Darwin and Son Francis Darwin did experiments like this.

Frits Went

Placed in agar identified how a growth producing chemical causes a coleptile to bend towards light. (Dark side had a higher concentration of auxin

Polar transport

unidirectional transport from the apical to the basal end through cell to cell, not gravity dependent but does require energy. At high concentrations it may produce Ethylene which inhibits cell elongation.

Acid Growth Hypothesis

H comes into nest of microfibrils, pH up, connections broken, reduced turgor pressure, allows H2O into cell, also activates expansins which break down the cross links(hydrogen bonds) between cellulose.

24D

A synthetic auxin that is used as a herbidicis, elimates eudicots in particuklar such as dandieloions. Auxin also produces secondary growth in vascular cambium and influences differentation of secondary xylem.

Cytokinins

Found by OVERBEEK, is a modified form of adenine. Stimulate cell division, the most common is zeatin discovered first in maize. Produced in actively growing tissue, often act with auxin to influence the pathway of cell division

Callus

A cluster of undifferentiated cells

Gibberllins

Discovered by Kurowasa caused by a fungus genus gibillera, also function in stem growth, fruit growth and seed germination;. Cause cell wall loosening
(Thomas seedling grapes), stimulates a-amylase to mobilize stored nutrients

Brassinosteriods

Chemically similar to steroids, induce cell elongation nd division in stem segments..(CHORY)., Growth promoting capacity, influence seed germination, flowering, absission, maturation and senescene, confers resistance to plants against abiotic stress

Abscisic Acid

Plant hormone that Inhibits cell division in buds and vascular cambium(ABA). No longer thought to play a major role in bud dormancy or leaf abcission. May increase 100 fold during seed germination(to try and INHIBIT germination). Helps plants withstand drought, BY causes an increase in outwardly directed potassium channels(K+) in the plasma membrane of guard cells.

Triple response

Growth maneuver that enables the shoot to avoid an obstacle; includes (1) slowing of stem elongation, (2) thickening of the stem, and a (3) curvature that causes the stem to start growing horizontally. Caused by the gas hormone (ETHYLENE)

Photomorphogenesis

Effects of light on plant morphology

Action Spectrum

A graph that depicts the relative effectiveness of different wavelengths of radiation in driving a particular process. 660 nm best. 730 nm (far red) INHIBITS germination. The LAST(Ultima) flash determined the seeds response.

Cicadarian Rythms

Cycles lasting about 24 hours And 11 minutes and common to all eukaryotic life. Is endogenous

Florigen

A flowering signal, not yet chemically identified, that may be a hormone or may be a change in relative concentrations of multiple hormones.

Cotransport

The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.

Endogenous

Produced within the body

Zeatin

the most prevalent cytokinin(a cell division stimulant in higher plants that also act with auxin) (e.g. coconut endosperm has a lot)

Megapascals

water potential is measured in what, 1 MPa is equal to about 10 atmospheres of pressure

Endodermal Cell

The casparian strip is found in every radial and transverse ________________.

Solute potential

A component of water potential that is proportional to the number dissolved solute molecules in a solution and measures the effect of solutes on the direction of water movement; also called somotic potential, it can be either zero or negative.

Plasmolyze

To shrink and pull away from a cell wall, or when a plant cell protoplast pulls away from the cell wall as a result of water loss.

Vacuolar Membrane

A membrane that encloses the central vacuole in a plant cell, separating the cytosal from the vacuolar contents, called cell sap; also known as the tonoplast. (90%) of the protplasts volume

Bulk Flow

The movement of water due to a difference in pressure between two locations. Is Solar Powered BECAUSE IT DEPENDS ON THE ACTIVE TRANSPORT OF SUGAR AT THE CELLULAR LEVEL.

Mycelium

Many hyphae tangled together into a thick mass; which comprise the bodies of multicellular fungi, when a plant is enowed with this it enables older roots to gain more water and soil than they could reach by themselves

Suberin

Fatty WAXY material found in the cell walls of cork tissue and in the Casparian strip of the endodermis

Transpiration

Process by which plants that release water into the atmosphere from small pores on their leaves known as stomata

Cyclin

one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells

Kinase

An enzyme that phosphorylates something else. Are frequently used in regulatory pathways, phosphorylating other enzymes.

CDK

Cyclin-dependent kinases. A protein kinase that is active only when attached to a particular cyclin. Activity rises and falls depending on the concentration of the cyclin partner.

Root Pressure

The upward push of water within the stele of vascular plants, caused by active pumping of minerals into the xylem by root cells, Usually happens at night when transpiration is very low to zero.

Acetylcholine

the neurotransmitter substance that is released at the synapses of parasympathetic nerves and at neuromuscular junctions, acts to activate muscles by releasing Ca2+ from the sarcoplasmic reticulum.

Cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

ATP Synthase

A cluster of several membrane proteins found in the mitochondrial cristea (and bacterial plasma membrane) that function in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion concentration gradient to make ATP. Provide a port through which hydrogen ions diffuse into the matrix of a mitrochondrion.

Cotransport

The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient. Is responsible for the Uptake of Surose by plant cells

CAM Plant

A plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions, first discovered in the family Crassulaceae. Carbon dioxide entering open stomata during the night is converted into organic acids, which release CO2 for the Calvin cycle during the day, when stomata are closed.

PEP Carboxylase

An enzyme that adds CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate in C4 plants. It acts prior to photosynthesis.

Rubisco

Ribulose carboxylase, the enzyme that catalyzes the first step of the Calvin cycle (the addition of CO2 to RuBP, or ribulose bisphosphate) in C3 Plants.

C3 Plants

A plant that uses the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three-carbon compound as the first stable intermediate. (95% of the plants on Earth)

Glucose 1 Phosphate

This molecule is initially released from the end of a glycogen molecule in the process of glycogenolysis

Amyoplast

colorless plastids that store starch

Amylopectin

branches in starch to help with packing branches consist of alpha 1-6 linkages between glucose molecules and branched starches (70%)

Xerophytes

Plants that have adapted by altering their physical structures. Often have few or no leaves(which if found , which reduces water loss.

Translocation

movement of sugars from photosynthesis from the leaves through the phloem of a plant , mainly through the sieve tube members.

Sieve Tube Members

The MAIN conducting cells in the phloem tissue that lack a nucleus, but are long and cylindrical for conducting sugar water(acting to maximize the cross sectional area).

Sugar Source

A plant organ in which sugar is being produced by either photosynthesis or the breakdown of starch. Mature leaves are the primary __________ of plants

Sugar Sink

A plant organ that is a net consumer or sorer of sugar. Growing roots, shoot tips, stems, and fruits sugar sinks supplied by phloem.

Transfer Cells

A companion cell with numerous in-growths of its wall, increasing the cell's surface area and enhancing the transfer of solutes between apoplast and symplast.

Van Helmont

Conducted an experiment to find out if plants grew by taking material out of the soil; concluded that most of the mass was gained from the water--he was partially right (WRONG) CO2

Stephen Hales

suggested that conserving green plants preserved rainfall. His ideas were put into practice in 1974 on the Caribbean island of Tobago, where about 20% of the land was marked as 'reserved in wood for rains' (1)

Rafflesia Arnoldii

the world's largest flower, with a blossom 3 feet wide,found only in Asia

Alteration of Generations

a life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte

Anthers

Part of a plant that contains male sex cells. Mendel removed these from some pea plants to be sure his plants would cross-pollinate and not self-pollinate

Ovules

A structure that develops within the ovary of a seed plant and contains the female gametophyte.

Carpel

The ovule-producing reproductive organ of a flower, consisting of the stigma, style, and ovary.

Pistil

the female ovule-bearing part of a flower composed of ovary and style and stigma

Sepal

A modified leaf in angiosperms that helps enclose and protect a flower bud before it opens

Style

The stalk of a flower's carpel, with the ovary at the base and the stigma at the top.

Stigma

sticky portion at the top of the style where pollen grains frequently land

Receptacle

The base of a flower; the site of attachment of the 4 floral organs to the stem.

Ovary

a structure containing egg cells; the base of a pistil in a flower

Floral Organs

Modified leaves because of
-genetic manipulation of FLORAL GENES
-Similar architecture between some floral organs and leaves

Internodes

A segment of a plant stem between the points where leaves are attached

Complete Flowers

a flower that has all four basic floral organs: sepals, petals, stamens, and carpals

Incomplete Flowers

a flower in which one or more of the four basic floral organs are either absent or nonfunctional

Superior Ovary

sepals, petals, stamens attached below the ovary

Sem Inferior Ovary

Whaen an ovary is on the same line as stamen, petals, and sepals

Inferior Ovary

in this floral morphology, the ovary is seated below the stamens, petals, and sepals

Inflorescences

flower clusters, borne together on a stem (as opposed to roses, which have one flower per stem))

Microsporangia

Sporangium that produces spores that give rise to male gametophytes.Are very notable in spikemosses, and a minority of ferns. In Gymnosperms and Flowering plants, the microsporangium is contained within a pollen grain

Microsporocytes

found in microsporangium; divides by meiosis, producing 4 haploid microspores; which then develops into a pollen grain (a male gametophyte enclosed within the pollen wall). These are also called Microspore Mother Cells

Microspore

A spore from a heterosporous plant species that develops into a male gametophyte. As it undergos mitosis and cytokinesis it produces two separate cells, (The Generative Cell and Tube Cell)

Generative Cell

A cell of the male gametophyte or pollen grain in seed plants that divides to give rise directly or indirectly to sperm.

Tube Cell

That nucleus of a pollen grain believed to influence the growth and development of the pollen tube. Also known as tube nucleus.

Megasporocyte

a single cell, which grows in the sporangium. grows and undergoes meiosis to produce four haploid megaspores, one of which will become an egg

Synergids

two very short lived cells that flank the egg cell and function in the attraction and guidance of the pollen tube to the embryo sac

Pollination

the transfer of pollen from male reproductive structures to female reproductive structures in plants

Integuments

Layers of sporophyte tissues that contribute to the structure of an ovule of a seed plant.

Self incompatability

the ability of a plant to reject its own pollen and sometimes the pollen of closely related individuals, Usually involves S Genes

Pin Flowers

long stigma and short anthers

Thrum Flowers

thrum (high male...caleb)
pin (stigma high...everything else low...low female...coco)
a mechanism to avoid self-fertilization

S Genes

Help in the recognition of the alleles for self incompatibilty, and bl=ock pollen tube growth if an ellele from pollen is recognized.

Double Fertilization

A mechanism of fertilization in angiosperms in which two sperm cells unite with two cells in the female gametophyte (embryo sac) to form the zygote and endosperm.

Micropyle

in the ovules of seed plants, the opening in the integuments through which the pollen tube usually enters

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