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Biology 101
1st semester
269
Biology
Undergraduate 3
12/17/2010

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Term
Reductionism
Definition
learning about a structure by studying its parts
Term
emergent properties
Definition
characteristics not found at lower levels which is particular for each level [populations have populaton density, age structure, etc; but this does not apply to individuals but to them as a whole]
Term

cellular respiration

[for producers or autotrophs]

Definition

process taht releases some of the energy stored in the nutrient molcules


 

carbon dioxide + water + light energy = sugars (food) + oxygen

Term

cellular respiration

[for consumers or heterotrophs]

Definition

process that releases some of the enrgy stored in the nutrient molecules

 


 

sugars (and other food molecules) + oxygen = carbon dioxide + water + energy

Term
deductive reasoning
Definition
begins with general principle
Term
inductive reasoning
Definition
begins with specific observations
Term
paradigm
Definition
set of assumptions or ceoncepts that consittute a way of thinking about reality [a change would be considered a paradigm shift]
Term
Domains?
Definition
Archaea ; Bacteria ; Eukarya
Term
Kingdoms?
Definition
Archaea ; Bacteria ; Protista ; Plantae ; Fungi ; Animalia
Term
Taxonomy : naming an organism
Definition
first genus ; second specific epithet [species]
Term
the hierarchy of biological organization
Definition
chemical level ; cellular level ; tissue ; organ ; organ system ; organim ; population ; community ; ecosystem ; biosphere
Term
atomic number
Definition
number of protnos or electrons
Term
atomic mass
Definition
how much matter it contains where it 1amu equals the mass of a proton and neutron
Term
redox reaction
Definition
the transfer of an electron that also inovoles the transfer of the nergy of that electron
Term
oxidation
Definition
loss of electron
Term
reduction
Definition
gain of electrons
Term
hydrophilic interactions
Definition
intereactions with water molecules [have an affinity for water or are "water loving"] polar molecules
Term
hydrophobic interactions
Definition
interactions between nonpolar molecules or "water fearing"
Term
heat
Definition
total kinetic energy of the particles within a given substance
Term
temperature
Definition
average kinetic energy of the particles in a given substance
Term
specific heat
Definition
amoutn of energy required to raise the temperature of water
Term
heat of vaporization
Definition
amount of heat energy required to change 1 g of a substance fromthe liquid phae to the vapor phase
Term
acid
Definition
a substance that dissociates in solution to form H+ ions and and anions
Term
base
Definition
substances that dissociate to yield OH- and cations
Term
calculating the pH values and OH- or H+ ion concentrations
Definition

[H+][OH-] = 1x 10^-14


example: [H+] = 10^-2

                             [OH-] = 10^-7 [-14- (-x)]

log [H+] =  pH value [positive value]

 

Term
electrolytes
Definition
when a salt, an acid, or a base is dissolved in water, it dissociated ions can conduct an electric currect
Term
nonelectrolytes
Definition
sugar, alcohols, and many other substances taht do not form ions when dissovled in water, and do not conduct an electric current
Term
salt
Definition
compound in which the hydrogen ion of an acid is replaced by some other cation [NaCl]
Term
isomers [what kinds are there?]
Definition

have the same molecular formular but different structures


structural isomers= difference in covalent arrangements between atoms


geometric isomers = difference in spatial arrangement [cis ; trans]


enantiomers = mirror like images of each other

Term
polymers
Definition
produced by linkng small organic compounds called monomers and can be degraded by hyrdolysis [linked by condensation reactions]
Term
hexoses
Definition
six-carbon sugars
Term
glycosidic linkage
Definition
linkage that consists of oxygen that is connected to two carbons to forma a dissacharide
Term
polysaccharide
Definition
macromolecules consisting of repeating units of simple sugars
Term
glycogen
Definition
alpha 1-4 linkages
Term
triglycerols
Definition

consists of glycerol joined to three fatty acids and formed by three condensation reactions

[image][image]

Term
ester linkage
Definition
covalent linkage between glycerol's hydroxl grops and carboxyl group on fatty acid
Term
globular proteins
Definition
rightly folded polypeptid chains that form long fibers, rougly spherical shapes
Term
molecular chaperons
Definition
mediate the folding of protein molecules
Term
nucleic acid
Definition
transmit hereditary information and determines what proteins a cell manufactures (DNA and RNA); polymers of nucelotides; consist of [deoxyribose or ribose ; one or more phosphate groups ; nitrogenous base (purine or pyrimidine)
Term
saturated fatty acids
Definition
solid at room temperature because they have no double bonds, which lead a greater amount stacked on top of one another by van der Walls interactions of hydrophobic molecules or nonpolar molecules [palmitic acid]
Term
monounsaturated fatty acids
Definition
contain one double bond; not fully saturated with hydrogen; tend to be liquid [trans fatty acid are an exception: they are technically monounsaturated fatty acids but the trans arrangement of the double bond allow for more hydrogen bonding and thus, it is a solid at room temperature]
Term
polyunsaturated fatty acids
Definition
two or more double bonds; tend to be liquid at room temperature
Term
primary structure of a protein
Definition
consists of the sequence of amino acids joined by polypeptide bonds [C-N]
Term
secondary structure of a protein
Definition

alpha helix is due to the hydrogen bonding to the oxygen

beta-helix  is due to hydrogen bonding of two polypeptide chains that results in the fold back

Term
tertiary structure
Definition
overal shape due to hydrogen bonds betwen R gorups, ionic bond between negative and positive charges, hydrophobic interactions of nonpolar molecules, and covalent bonds with any disulfide functional groups if any are present
Term
microvilli
Definition
fingerlike projections of the plasma membrane that increases the surface area-to volume
Term
cell fractionation
Definition
technique for purifying different parts of the cell so taht they can be studied separately
Term
nucleoli
Definition
not enclosed by a membrane; contains a nucleolar organizer, made up of chromosomal regions containing instruction for making the type of RNA in ribosomes
Term
perioxisomes
Definition
membrane-enclosed organelles containing enzymes that catalyze an assortment of metabolic reactions in which hydrogen is transferred from vairous compounds to oxygen
Term
plastids
Definition
a group of organelles that produce and store food materials in cells of plants and algae
Term
chromoplasts
Definition
are produced when proplastids are stimulated by exposure to light
Term
leukoplasts
Definition
unpigmented plastids; they include amyloplasts
Term
kinesin
Definition
moves organelles toward the plus end of a microtubule
Term
dynein
Definition
transports organelles to the negative side of a microtubule [retrograde transport]
Term

centromere microtubule structure?

flagella or cilia microtubule structure?

 

Definition

centromere [9x3]

flagella or cilia [9+2]

Term
exergonic reaction
Definition
releases energy and is said to be spontaneous
Term
endergonic reaction
Definition
gain in free energy [delta G is positive]
Term
coupled reactions
Definition
exergonic reactions that drive the endergonic reactions
Term
ADP
Definition
formation from the phosphorlyation reactions that transfers a phosphate group from ATP to a compound forming ADP
Term
allosteric inhibitors
Definition
bind to the allosteric site of an enzyme which changes the shape of the enzyme and doesn't allow for the subtrate to bind to the enzyme [inhibits an ES complex]
Term
catabolism
Definition
releases energy by splitting complex molecules into smaller components
Term
anabolism
Definition
the synthesis of complex molecules from simpler building blocks
Term
dehydrogenations
Definition
two hydrogen atoms are removed from the substrate and transferred to NAD+ or FAD
Term
Decarboylations
Definition
reactions in which part of a carboxyl group is removed from the substrate as a molecule of CO2
Term
anaerobic respiration
Definition
do not use oxygen as the final electron acceptor and is performed by some prokaryotes [nitrogen cycle]
Term
facultative anaerobes
Definition
carry out aerobic respiration when oxygen is available but switch to fermentation when there is lack of oxygen
Term
chlorophyll a
Definition
the pigment that initiates the light-dependent reactions of photosynthesis [functional group : methyl group]
Term
chlorophyll b
Definition
accessory pigment that also participates in photosynthesis [functional group = aldehyde]
Term
engelmann's experiment
Definition
exposed spirogyra cells to a color spectrum and saw where the bacteria swam to
Term
photosynthesis
Definition
reactions divided into two phases, the light-dependent reactions and the carbon fixation reactions where ATP and NADPH are the products of the light-dependent reactions and carbohydrates ar produced during the carbon fixation reactions
Term
photosystem I
Definition
consists of a pair of chlorophyll a molecules with an absorption peak at 700 nm and is referred to as P700
Term
photosystem II
Definition
made up a pair of chlorophyll a molecules with an absorption peak of about 680 nm and is referred to as P680
Term
photorespiration
Definition
occurs in the present of light and as in aerobic respiration, it requires oxygen and produces CO2 and H2O
Term
chromosome
Definition
physical carriers of genes
Term
histones
Definition
proteins that facilitate chromosome packaging
Term
nucleosome
Definition
Histone + DNA strands
Term
scaffolding proteins
Definition
nonhistone proteins that help maintain chromosome structure in extended chromatin
Term
condensin
Definition
proteins that are required for chromosome compaction
Term
centrioles
Definition
located in the middle of each mictrotubule-organizing center.  surrounded by fibrils that make up the peri-centriolar material
Term
cohesion
Definition
sister chromatids are physically linked by this ring-shape protein that extends along the length of the sister chromatid arms and are particularly concentrated at the centromere
Term
protein kinases
Definition
enzymes that activate or inactivate other proteins by adding phosphate groups to them
Term
cdks
Definition
protein kinases involved in controlling the cell cycle and of which are only active when they bind to cyclins
Term
cytokinins
Definition
hormones that stimulate mitosis in plants
Term
growth factors
Definition
proteins that stimulate mitosis in some animals cells
Term
circardiam rhythms
Definition
help an organism detect the time of day
Term
photoperiodism
Definition
enables a plant to detect the time of year
Term
snaptonemal complex
Definition
forms along the entire length of the synapsed homologous is thought to play a role in crossing over
Term
chiasmata
Definition
location where the homologous chromosomes are held together because the centromeres and kinetochores of the homologous chromosomes become separated from one another
Term
interkinesis
Definition
brief period between interphase 1 and prophase 1 that dictates no S phase
Term
alleles
Definition
alternative forms of a gene
Term
locus
Definition
segment of the DNA that has the information for controlling some aspect of the structure
Term
monohybrid cross
Definition
inheritance of two different alleles of single locus
Term
homozygous
Definition
two alleles for a particular locus that are identical in the organism
Term
heterozygous
Definition
two alleles for a particular locus that are different in the organism
Term
genotype
Definition
genetic constitution of that organism expressed in symbols
Term
dihybrid cross
Definition
inheritance of different alleles at two loci
Term
linked gene (linkage)
Definition
tendency for a group of genes on the same chromosome to be inherited together in successive generation because of the closeness in loci locations
Term
recombination
Definition
any process that leads to a new gene combination
Term
map unit
Definition
1% recombination between two loci = 1 map unit
Term
hemizygous
Definition
male has only one copy of each X-linked gene
Term
dosage compensation
Definition
mechanism that makes equivalent the two doses in the famle and the single dose in the male [creation of a Barr body noticable in prophase]
Term
variegation
Definition
when th x chromosome inactivation in a heterozygous female produces about halfo her cells with one of the alleles and half with the other alleles
Term
incomplete dominance
Definition
when the heterozygote has a phenotype intermediate between those of its two parents (baby plant from red and white is pink)
Term
codominance
Definition
instances in which the heterozygote simultaneously expresses the phenotypes of both typesof homozygote (cow separated red and white hairs)
Term
mutiple alleles
Definition
three or more alleles for a given locus exist with the population
Term
pleiotropy
Definition
the ability of single gene to have multiple effects
Term
epistasis
Definition
presence of certain alleles of one locus can prevent or makr the expression of alleles of a different locus and express their ow phentoype instead
Term
polygenic inheritance
Definition
multiple independe pairs of genes that have similar and additive effects on the same character
Term
norm of reaction
Definition
the range of phenotypic possibilites that can develop from a single genotype under different enviromental conditions
Term
crossing over
Definition
more likely to occur between two loci if they lie far apart on the chromosome and less likely to occur if they lie close together
Term
virulence
Definition
ability to cause disease
Term
avirulence
Definition
inability to cause disease
Term
transformation
Definition
genetic change in which the properties of one strain of dead cells are conferred on a different strain of living cells
Term
chargaff's rule
Definition
in double stranded DA molecules, the number of purines match the number of pyrimidines [A-T ; G-C]
Term
x-ray diffraction
Definition
method for elucidating the 3-D structure of a molecule by determining the distances between atoms using x-rays to be diffracted by each atom
Term
semi-conservative replication
Definition
when DNA double helixes would split and replicate afterwards, having an original strand of DNA in both double helixes
Term
conservative replication
Definition
both parent strands would remina together, and the two synthesized strands would forma second double helix
Term
dispersive replication
Definition
the parental and newly synthesized strands might become randomly mix during the replication process
Term
density gradient centrifugation
Definition
separating large molecules such as DNA on the basis of difference in their density when using a heavy isotope of nitrogen to label the bases of the DNA strands, making them more dense
Term
mutations
Definition
genetic changes that arise in gees and then transmitted faithfully to succeeding generations [nucleotides improperly paired with their counterparts]
Term
DNA polymerase
Definition
enzymes that catalyze the linking of successive nucleotide subunits by adding nucleotides to the 3'end
Term
nucelotide excision repair
Definition
three enzymes cut out the damaged DNA [DNA polymerase adds the correct nucleotides, and DNA ligase closes the break
Term
telomeres
Definition
important genetic information that is retained becaue chromosomes have these protective end caps
Term
telomerase
Definition
can lengthem telomeric DNA by adding repetitive nucleotid sequences to the ends of eukaryotic chromosomes [poopular in cancer cells]
Term
toposiomerases
Definition
produce breaks in the DNA molecules ir order to releive strain when DNA replication is taking place [unwinding rope causes tension towards the bottom]
Term
reading frame
Definition
reading the code, one triplet at a time
Term
promoter
Definition
the nucleotide sequence in DNA to which RNA polymerase and associated proteins initially bind
Term
polyribosome
Definition
an mRNA molecule that is boudn to cluster of ribosomes
Term
small nuclear RNA
Definition
molecules that bind to specific proteins to forma a small nuclear ribonucleoprotein complex, which int run, combines with other snRNPs to form a splicesome
Term
signal-recognition particle RNA
Definition
directs the ribosome mRNA polypeptide complex to the rough ER
Term
small nucleolar RNA
Definition
processes pre-mRNA molecules inthe nucelolus during ribosome subunit formation
Term
siRNA
Definition
double stranded molecules
Term
gene
Definition
a DNA nucleotide sequence
Term
alkaptonuria
Definition
rare genetic disease that made the patient's pee turn black when exposed to air
Term
mutagens
Definition
types of mutations that include variuos types of radiation,such as ultraviolet rays
Term
carcinogens
Definition
agents that cause cancer
Term
transcpription-level control
Definition
regulation that controls the production of enzymes and other proteins when they are needed
Term
consitutive genes
Definition
genes which are constantly transcribed
Term
operons
Definition
facilitate the coordinated control of functionally related genes
Term
structural gene
Definition
enzyme-coding structure
Term
heterochromatin
Definition
inactive genes [Barr body]
Term
genomic imprinting
Definition
phenotypic expression of certain genes is determined by whether a particular allele is inherited from the female or male
Term
gene amplification
Definition
genes which are selectively replicated in those cells
Term
TATA box
Definition
eukaryotic promoter
Term
leucine zipper proteins
Definition
nickname for transcription factors because they are held together by the side chains of leucine and other hydrophobic amino acids
Term
kinases
Definition
enzymes that add phosphate groups
Term
enzymes that remove phosphate groups
Definition
Term
proteases
Definition
hydrolyze some of the peptide bonds, degrading the protein to short, nonfunctional peptide fragments
Term
temporal regulation
Definition
mechanism in control for some genes taht are only unducible during certain period in the life of the organism
Term
cosmid cloning vectors
Definition
combination vectors with feature from both bacteriophages and plasmids
Term
bacterial artificial chromosomes
Definition
accomodates much larger fragments of DNA
Term
recombinant plasmids
Definition
produced by mixing the two kinds of DNA under conditions that promote hydrogen bonding of complementary bases
Term
polymerase chain reaction
Definition
technique for amplifiying DNA in vitro
Term
southern blot
Definition
separating DNA fragments by gelelectrophoresis and then transferring themto a nitrocellulose or nylon membrane
Term
norther blot
Definition
studying RNA molecules by separating by electrophoresis which ar then transferred to a membrane
Term
western blot
Definition
a blot consisting of proteins or polypeptides previously serparated by gel electrophesis
Term
RFLP
Definition
DNA mutations taht are caused by the result of different lengths of fragments produced by a given restriction enzyme
Term
expressed sequence tages
Definition
helps indentify protein-coding genes
Term
mutagenesis screening
Definition
treating male mice with chemical mutagens taht cause mutations in DNA
Term
DNA microarrays
Definition

studying patterns of gene expression

 

Term
transgenic organisms
Definition
plants and animals in which foreign genes have been incorporated
Term
recombinant DNA technology
Definition
researches splic together DNA from different organims in the laboratory. one goal of this technology is to enable scientists to obtain many copies of a specific DNA segment for the purpose of studying it
Term
cytogenetics
Definition
study of chromosomes and their role in inheritance
Term
genomic imprinting
Definition
the expression of a gene in a given tissue or development stage that is based on its parental origin
Term
gene targeting
Definition
produces strains of mice that were either hymozygous or heterozygous for a disease
Term
polyploidy
Definition
presence of multiple sets of chromosome
Term
aneploides
Definition
single extra chromosme or the absence of a chromosome
Term
nondisjunction
Definition
abnormal meiotic division in whcih chromsomes fail to separate at anaphase
Term
inversion
Definition
orienatation of a chromsome segment is reversed
Term
translocation
Definition
chrosome fragment breaks off and joins with a nonhomologous chromsome
Term
deletion
Definition
breakage that causes loss of part of chromsome, along with the genes on that segment
Term
translocation
Definition
two nonhomologous chromosomes exchange segments
Term
consanguineous matings
Definition
matings between genetically related individuals
Term
protobionts
Definition
assemblages of abiotically produced organic polymers which often divid half, maintain an interal chemical environment, and the beginnings of metabolism
Term
microspheres
Definition
a type of protobiont formed by adding water to abiotically formed polypeptides
Term
microfossils
Definition
ancient remains of microscopic life
Term
stromalites
Definition
rocklike columns composed of many minute layers of prokaryotic cells
Term
serial endosymbiosis
Definition
organelles such as mitochondria and chloroplasts that may have originated from mutually advantagous symbiotic relationships between two prokaryotic organisms
Term
lysogenic conversion
Definition
when a temperate virus reverst to a lytic cycle and then deestroys the host (possibly due to ultra-violet exposure)
Term
retroviruses
Definition
RNA virus taht have a DNA plymerase called reverse transciptase,which is used to transcibe the RNA genome into a DNA intermediate.  this DNA becomes integrated into the host DNA b an enzyme also carried by the virus (HIV)
Term
viroid
Definition
much smaller than a virus and consist of very short strands of naked DNA
Term
prion
Definition
misfolded of the PrP protein
Term
peptidolycan
Definition
consists of two unusually types of sugars linked with short polypeptides
Term
gram-positive
Definition
bacteria that absorb and retain crystal violet stain in the labortatory (penicillin works for this)
Term
gram-negative
Definition
do not retain the stian when rinsed in alcohol
Term
capsule
Definition
slime layer that surrounds the cell wall
Term
chemotaxis
Definition
movement in response to chemicals in the enviroment
Term
F+ cells (donor cells)
Definition
DNA that can be transmitted to recipient cells
Term
F- cells
Definition
DNA sequence known as the F factor that is necessary for a bacterium to serve as a donor during conjugation
Term
biofilms
Definition
dense films of bacteria
Term
coenocytic
Definition
consisting of multinucleate mass of cytoplasm
Term
plankton
Definition
made up of mostly by protists, the floating organims
Term
monophyletic
Definition
evolved from a common ancestor
Term
paraphyletic
Definition
kingdom contains some, but not all, of the descendants of a common eukaryote ancestor
Term
trichnymphs
Definition
specialized excavates with hundreds of flagella that live in the guts of termites and wood-eating cockroaches
Term
pellicle
Definition
outer covering
Term
trypanosomes
Definition
colorless discritates, many of which are parasitic and cause disease
Term
hypotrichs
Definition
greatly modified cilia that are part of the ciliates
Term
isogamous
Definition
sexual reproduction
Term
anisogamous
Definition
sexual reproduction involving the fusion of two flagellate gametes of different sizes
Term
oogamous
Definition
produce a nonmotile egge and a flagellate male gamete
Term
index fossils
Definition
markers to help indentify sedimentary rock layers
Term
chitin
Definition
polymer that consists of subunits of nitrogen-containing sugar which is located in the cell walls of fungi
Term
conidiophores
Definition
specialized hyphae that produce asexual spores called conidia
Term
gametangia
Definition
tips of the hyphae come together
Term
mycorrhizae
Definition
symbiotic relationships between fungi and the roots of plants
Term
endomycorrhizal fungi
Definition
fungi that have mycorrihae relationships that ultimately have the plasma membrane of the cells surround the hyphae [fingers pushing through glove]
Term
homothallic
Definition
self-fertile
Term
microphyll
Definition
single vascular strand
Term
megaphyll
Definition
stem branches that gradually fill in with additional tissue to form most leaves
Term
dichotomous branching
Definition
forking of the stem
Term
calyx
Definition
term for all the sepals of a flower
Term
progymnosperm
Definition
two derived features absent in their immediate ancestors; leaves with branching veins and woody tissue similar to taht of modern gymnospers; gave rise to conifers and seed ferns
Term
coevolution
Definition
mutual adaptation between plants and animal pollinators
Term
core angiosperms
Definition
comprise magnoliids, monocots, and eudicots
Term
primary growth
Definition
increase in stem and root length
Term
secondary growth
Definition
increase in the girth of a plant
Term
vascular cambium
Definition
layer of meristimatic cells that froms a long, thin, continous cylinder within the stem and root
Term
cork cambium
Definition
composed of a thin cylinder or irregular arrangment of meristematic cells
Term
alternate leaf arrangement
Definition
one leaf at each node
Term
opposite leaf arrangement
Definition
two leaves grow at each node
Term
whorled leaf arrangement
Definition
three or more leaves grow at each node
Term
epidermis of leaves
Definition
colorless and do not undergo photosynthesis
Term
cutin
Definition
what the cuticle is made out of
Term
trichomes
Definition
hairlike structures which help reduce water loss from the leaf surface
Term
palisade mesophyll
Definition
located unerneath the upper epidermis, main site of photosynthesis
Term
spongy mesophyll
Definition
located on top fo the lower epidermis; allows for diffusion of gases
Term
bundle sheath
Definition
one or more layer so nonvacular cells that surround the larger veins
Term
patch clamp technique
Definition
reasearchers seal the tip of a micropipette to a tiny patch of a membrane that contains a single ion channel
Term
guttation
Definition
loss of liquid water.  unlike dew (which condenses from cool night air) guttation droplets come from within the plant
Term
abscission
Definition
trees shed leaves, whcih is particularly orchestrated by changing levels of ethylene
Term
middle lamella
Definition
cement that holds the primary cell walls of adjacent cells together
Term
tendrils
Definition
climbing plants need this to help keep the vine attached to the structure on which it is growing
Term
buds
Definition
embryonic shoots
Term
terminal bud
Definition
embryonic shoot located at the tip of stem
Term
bud scales
Definition
coverings of a apical meristem of a terminal bud
Term
pith rays
Definition
areas of parenchyma between the vascular bundles
Term
pressure-flow hypothesis
Definition
solutes move in phloem by means of a pressure gradient
Term
adventitious roots
Definition
the main roots of a fibrous root system that arise from the stem
Term
symplast
Definition
continnum of living cytoplasm, whcih is connected from one cell to the next cell by cytoplasmic bridges called plasmodesmata
Term
apoplast
Definition
interconnected porus cell walls of a plant, along which water and mineral ions moves freely
Term
endodermis
Definition
regulates the movement of water and minerals that enter the xylem in the root's center
Term
casparian strip
Definition
band like region which pertains to endodermal cells
Term
aquaporins
Definition
integral membrane proteins that facilitate the rapid transport of water across the membrane
Term
stele
Definition
center of eudicot primary root, in which the outermost layer is the pericycle
Term
pith
Definition
ground tissue found in the center of stems and root which are not found in primary eudicot roots
Term
vascular cambium gives rise to...
Definition
secondary growth, for which no monocots have but eudicots do
Term
prop roots
Definition
adventitious roots that develop from branches or a vertical stem and grow downward into the soil to help support the plant in an upright position
Term
 buttress roots
Definition
holds the trees in an upright and aid the extensive distribution of the shallow roots
Term
pneumatophores
Definition
breathing roots
Term
epiphytes
Definition
plants that grow attached to toher plants
Term
arbuscules
Definition
when the fungus penetrates cell walls of the root cortex and forms these branches
Term
rhizobia
Definition
nitrogen-fixing bacteria
Term
soil particles
Definition
sand, silt, clay
Term
humus
Definition
the partly decayed organic portion of the soil
Term
leaching
Definition
removal of dissolved materials from soil by percolating water
Term
illuvation
Definition
deposition of leached material in the lower layes of soil
Term
radical
Definition
short embryonic root
Term
hypocotyls
Definition
the short portion of the embryionic shoort connecting the radical to one or two cotyledons
Term
plumule
Definition
shoot apex or terminal bud
Term
imbibtions
Definition
absorption of water by a dry seed
Term
coleptiles
Definition
sheath of cells pertaining ot corn and other grasses that surround and protect the young shoot
Term
tubers
Definition
thick ends of rhizomes
Term
corm
Definition
very short, erect underground stem
Term
stolons
Definition
horizontal, aboveground stems that grow along the surface and have long internodes
Term
plantlets
Definition
detachable notches along their leaf margins
Term
suckers
Definition
adventitious buds on roots
Term
apoximis
Definition
production of seed with sexual reproduction
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