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AP Biology Vocab

Biological Terms Encompassing the 4 Big Ideas

adaptation when features evolve for a particular organism to make them better suited to survive and reproduce in their environment
adaptive radiation numerous species emerge from a single common ancestor, giving way to diversity of opportunities and problems
allele an alternative form of a gene that results from a mutation; alleles are found at the same place on chromosomes
allopatric speciation when geographical barriers calls for the ancestral population to become segregated
amino acid a functional group consisting of two hydrogen atoms bonded to a nitrogen atom
analogous structures structures that are from different evolutionary origins, but have similar functions
antibiotic resistance occurs due to the improper use/abuse of antibiotics; the bacteria in the body do not respond to the antibiotics needed to cure the bacteria/infection
artificial selection selection of mates in plants and animals to allow for the occurrence of desired traits
background extinction rate standard rate of extinction before humans became a contributor to extinctions in geological and biological history
behavioral isolation species do not mate because of differences in their courtship
biogeography the study of species based on their past and present distribution patterns
biological species a group of organisms that has the ability to interbreed and produce offspring that are fertile
bottleneck effect a dramatic decrease in the size of a population that results after environmental or human causes
cladograms a diagram that depicts a cladistic (system of biological taxonomy) relationship amongst many species
clade a grouping of organisms that are thought to have evolved from one common ancestor
class a taxonomic rank in cladistics
coevolution an influence of species that are closely associated on one another in their evolution(s)
common ancestor an organism from which multiple organisms can claim descent
comparative anatomy the study of similar anatomical features on species.
convergent evolution the process of acquiring the same trait in lineages that are unrelated
crossing over an exchange of genes with homologous chromosomes that later results in parental characteristics being mixed in offspring
Darwin a naturalist who established a theory that all species have descended from common ancestors over the course of time.
diploidy the state of having two sets of chromosomes in somatic cells
differential selection A biased selection sample of organisms.
directional selection a mechanism of natural selection where a single phenotype is favored, which would cause the allele frequency of the population to shift in one direction over time
divergent evolution the process of accumulating differences amongst groups of organisms that eventually leads to the formation of new species
domain a taxonomic rank that is the highest rank of organisms
ecological isolation occurs when geographically co-occurring organisms are divided/separated by varying preferences ecologically
emigration the migration of an organism(s) out of a place of dwelling
epoch a time in history marked by notable events
evo-devo type of biology that compares the development processes of differnt organims to determine their ancestral relationship.
evolution process by which varying organisms develop and diversify from earlier form over the course of many generations
extinction when there is no more organisms of a certain species living
family a taxonomic rank below order and above genus
fertility the natural capability to produce offspring
fixation of alleles when an allele reaches a frequency of 100%
fossil a remain or an impression of an organism from prehistoric times that has been preserved in a petrified form
fossil record the history of life as documented and shown through fossils throughout the existence of life
Founder effect a severe loss of genetic variation that results from a population being established by a miniscule number of individuals from a previous larger population
gene flow the transfer of alleles of various genes from one population to another population over the course of time
gene pool the collection of various genes held within an interbreeding population
genetic drift the change in allele frequency in a given population because of random sampling within that population
genetic equilibrium a population is in genetic equilibrium when the frequency of alleles in the population does not change over the course of several generations
genetic variation the variation amongst alleles in and among populations
genotype the genetic make-up of a single organism
genus a taxonomic rank below family and above species
geographic isolation speciation that occurs when multiple populations of the same species become isolated from one another; which interferes with their ability to exchange genetic information between the populations
geologic time scale a measurement chronologically that is used by scientists to describe the relationship and relative timing of different events throughout the history of Earth
gradualism a hypothesis that the process of evolution occurs through the gradual accumulation of genetic changes over the course of time
Hardy-Weinberg equation p^2+2pq+q^2=1; where p^2 is the frequency of the dominant homozygous genotype, 2pq is the frequency of the heterozygous genotype, and q^2 is the frequency of the homozygous recessive genotype
Hardy-Weinberg equilibrium states that the frequencies of alleles and genotypes in a population will stay constant from one generation to subsequent ones if certain evolutionary influences are absent
heterotrophic requiring organic compounds of carbon and/or nitrogen for nourishment of the organism
homologous structures structures shared by multiple that don’t perform the same function, but have a common ancestral origin
homology a likeness in the same structures of different organisms
hybrid a genetic hybrid is one that is a carrier for two different alleles of the same gene
hybrid inviability an isolating mechanism in which a hybrid organism’s ability to mature into a fit and healthy adult is significantly reduced; a post-zygotic barrier
immigration the migration of an organism(s) into a place of dwelling that was previously foreign
inbreeding to breed from organisms that are closely (often immediately) related to each other over the course of many generations
isolation occurs when a population of individuals is separated from another species that is capable of breeding with the original population
kingdom a taxonomic ranking below domain and above phylum
last universal common ancestor said to have lived 3.5 to 3.8 billion years ago. It is the organism from which all life on earth descended.
limited resources the finite amount of resources available on the globe; competition exists to fight for access to this finite sum of resources
mass extinction a series of events that leads to a sharp decline in diversity on earth.
mechanical isolation a form of reproductive isolation that results from the incompatibility of the reproductive structures of a male(s) and female(s)
migration the movement of organisms from one location to another.
monomers a simpler molecule that can bond to other identical molecules in order to form a polymer
mutation a change in a gene’s structure that results in a variant form being created, which may be transmitted to future generations through reproductive processes
natural selection a gradual process in which organisms that are better suited for their environment have a higher rate of survival and will produce more offspring in their lifetime; leads to certain traits becoming more/less common over time in that population
outgroup in cladistics, an organismal group that is used as a reference for determining evolutionary relationships between monophyletic groups
paleontology the study of prehistoric life
panspermia the theory that life exists throughout the Universe, and has the capability to be spread throughout in the debris of various meteoroids, asteroids, and planets.
parallel evolution the development of similar trait(s) in related species that have descended from the same common ancestor, but in different clades
phenotype the observable, physical characteristics of an organism which is a result of the environment and genotype interacting over time
phylogenetic tree a diagram that shows the believed evolutionary relationships between different species based upon similarities in physical or genetic characteristics
phylogeny the portion of biology the relates to phylogenesis
polymorphism the occurrence of different forms among organisms.
polyploidy cells or organisms that have more than two homologous sets of chromosomes
population all the organisms of a species who reside in the same geographical area and are capable of interbreeding
postzygotic isolating mechanism a mechanism of isolation that makes a zygote nonviable or creates a sterile offspring; occurs after fertilization happens
prezygotic isolation mechanism a mechanism of isolation that prevents egg and sperm from meeting and fertilization; occurs before the fertilization
primordial environment first environment created.
protobiont a system believed to have possible been a past precursor to what would become prokaryotic cells
radiometric dating a means of dating geological specimens through the process of determining the proportions of a radioactive isotope in the sample being used
random assortment different genes will separate from one another independently when reproductive cells develop
random fertilization the fact that one of almost infinitely many kinds of sperm has the capability to fertilize an egg
random mating when the genotypes of two organisms don’t influence the choice of partner for sexual reproduction
relative dating science that determines the relative age of the earth and earth formations
reproductive isolation mechanisms, behaviors, and processes that prevent members of separate species from producing offspring, or produce offspring that are fertile
rock strata a layer of tissue
serial endosymbiosis process by which mitochondria, chloroplasts, and possibly other cellular structures were derived from smaller prokaryotes that were consumed by larger cells; poses the model for the origin of eukaryotes
sexual selection natural selection that comes from the preferences of one sex for a certain set of characteristics in members of the opposite sex
speciation the beginning of a new species in evolution
species a group of organisms whose members have anatomically similar structures and are capable of interbreeding with one another
stabilizing selection natural selection that, over time, will favor the intermediate forms of variants by acting against the extremes of phenotypes
sterility an inability to affect the process of sexual reproduction
stromatolite an organism made up of lime-secreting cyanobacteria and trapped sediment. One of first life forms on earth.
symbionts two organisms that live in symbiosis (mutually beneficial relationship) with one another
sympatric speciation speciation results from an extreme change in the genotypic ratios of a population, which isolates a smaller part of the population from the larger population
temporal isolation isolation that is the result of temporal differences between organisms in breeding (one mates in the summer, one mates in winter)
transitional fossil a fossil that shows the evolution of one species to another.
variation any difference between organisms within the same species
vestigial organs an organ/structure in an organism that has very little, if any, importance to the organism
viability the capability to grow and develop normally
zygotic mortality when an egg becomes fertilized, but the zygote fails to develop afterwards
abiotic not originating from living organisms; lacking life
abscisic acid hormone in plants that inhibits growth, promote being dormant, and helps it remain stable in stressful conditions
active transport when energy is required to move ions and/or molecules across a cell membrane from a region of low concentration to a region of higher concentration
adaptive radiation a variation of a group of organisms into forms which will fulfull varying niches in ecology
adhesion the process/action of adhering (frictional grip) to a surface
alcohol fermentation process by which carbon dioxide and and alcohol is produced from sugar by yeast
alimentary canal passage consisting of the esophagus, stomach, and intestines, along which food and nutrients pass through the body from the mouth through to the anus
alveoli small sacs of air in the lungs where oxygen and carbon dioxide exchange occurs
amphipathic describes a chemical compound that has both lipophilic and hydrophilic properties
anabolic reactions a reaction in which complex molecules are formed from simpler substances
anaerobic respiration the means of generating energy by oxidizing nutrients through an external electron acceptor that isn’t oxygen
annual in one growing season; the germination, flowering, and inevitable death occurring
antibodies antigen-binding immunoglobulin that acts as the effector in the immune response; antibodies are produced by B cells
antidiuretic hormone hormone that prevents your body from losing too much water
antigens a foreign molecule that doesn’t belong within an organism and causes an immune response to commence
apomixis a means of reproducing asexually in plants
apoptosis the process of programmed cell death in which cell fragments are produced (apoptic bodies) which are consumed by phagocytic cells and removed.
aquaporin proteins within the cell membrane that control the flow of water in and out of the cell
asexual reproduction a means of reproduction that occurs with only a single parent withou the fusion of gametes
atrium chamber of the heart that receives the blood returning back the heart from the rest of the body
ATP Adenosine triphosphate; provides temporary storage of energy in phosphodiester bonds
ATP synthase an enzyme that is able to synthesize adenosine triphosphate
autotrophs an organism that obtains organic materials without eating other organisms; use energy from the sun to make organic molecules
B cells lymphocyte that is developed within the bone marrow and produces antibodies that mediate humoral immunity
biennial any plant that takes up to two years to complete its entire life cycle
binary fission way in which prokaryotes reproduce; each daughter cell that results from the division receives a copy of the parental chromosome
biological clocks internal factors that occur rhythmically in the absence of external stimuli that an organism does on a day to day basis
biotic any living organisms in an environment
bronchi one of a pair of respiratory tubes that branch into one of the lungs at the end of the trachea
bronchioles subdivisions of the bronchi that become finer as they gather in the alveoli
budding means of propagation for asexual organisms in which outgrowths from the parent re formed and pinched off to live independently or they remain attached and form extensive colonies
Calvin cycle second stage of photosynthesis in which CO2 fixation occurs, and is then reduced to carbohydrates
carrier protein proteins that facilitate the movement of ions, small molecules, and other proteins across biological membranes
catabolic reactions releases energy by the breaking down of complex molecules into simple compounds
cell differentiation the divergence of cells by structure and function as they are specialized during an organism’s development
cell mediated immunity immunity that defends host cells against viruses, fungi, protists, and bacteria with specialized cells circulating the blood and lymphoid tissue
cell wall protective external layer to the plasma membrane of plant cells, fungi, bacteria, and some protists
cellulose polysaccharide of cell walls made up of glucose monomers
centrioles part of a cell that enters the ends during prophase and forms the spindal fibers; responsible for the division of animal cells
channel protein proteins found in the cell membrane that allow certain molecules/ions to pass through the membrane and into the cell
chemiosmosis a mechanism that uses stored energy in hydrogen ion gradients to fuel cellular work, also most of the synthesis of ATP occurs through chemiosmosis
chemosynthesis the synthesis of carbohydrates from water and carbon dioxide in some fungi and bacteria
chemotaxis the movement of an organism or cell in a direction that relates to a gradient of higher or lower concentration based on environmental cues
chitin a polysaccharide of an amino acid in the exoskeleton of arthropods
chloroplast an organelle in plant cells and photosynthetic protists that harnesses the sun’s light to fuel the synthesis of organic compounds
cholesterol a steroid that helps create a key part of cell membranes in animals and is a precursor to other steroids
ciliated flame cell cells found in simple freshwater dwelling invertebrates that act as kidney by removing waste materials from the organism
cillia microscopic and short hairlike structures located in large numbers on the surface of some cells that vibrate to propel the cell’s movement and/or act as a sensory organ
Circadian rhythm physiological cycle of approximately 24 hours eukaryotic organisms
cohesion the act of like molecules binding together; usually through hydrogen bonds
commensalism symbiotic relationship where one organism gains benefits, but the other organism isn’t helped or hurt by the relationship
communication behavior that consists of the transmission, reception, and response to signals from the environment
community all organisms inhabiting a certain geographical area
competence the ability to take in DNA and transform genetically
competitive exclusion principle when populations of similar species compete for the same limited resources one will utilize the resources at a more efficient rate than the other, and will gain a reproductive advantage over the other population which will eventually die off
competitive inhibitor any substance that can reduce enzymatic activity by entering the active site of the substrate being mimicked
concentration gradient an increased or decreased density in the substance of a chemical in one area
consumer an organism that gains its food and nutrients from feeding on other organisms/organic materials b/c it is incapable of creating its own food from inorganic materials
contractile vacuoles a membranous sac that moves excesses of water out of a cell
cooperativity in a protein; where a conformational change in one subunit is transmitted to all other protein subunits
countercurrent exchange the flow of adjacent fluids in opposite directions that helps maximize transfer rates in an organism
courtship behavior sequences of behavioral acts that occur before mating between males/females of the same species
cryptic coloration prey becomes difficult to see against its background due to its camouflage
cuticle an adaptation creating a waxy covering on the surface of stems and leaves to prevent desiccation; also the exoskeleton of an arthropod with layers of protein and chitin
cyclic AMP cyclic adenosine monophosphate - common intracellular signaling molecule (second messenger) in eukaryotic cells that is ring shaped and made from ATP
cyclic photophosphorylation ATP produced during the light dependent stage of photosynthesis; only photosystem one is used - light is absorbed by the photosystem and two electrons are released which are then accepted by the electron transfer chain and ATP is created
cytoplasm the contents of the cell, not including the nucleus, whichi s bounded by the plasma membrane
cytoskeleton combination of intermediate filaments, microfilaments, and microtubules that are networked throughout the cytoplasm and serve various mechanical and transport functions
cytotoxic T cells a lymphocyte that kills infected cells and cancer cells
dehydration reaction when two molecules covalently bond to one another as a water molecule is removed
diaphragm muscle at the bottom wall of the thoracic cavity in mammals that takes part in ventilating the lungs
diffusion tendency of a substance to move down its concentration gradient from an area that is more concentrated to an area that is less concentrated
diploid cell a cell that contains a set of chromosomes inherited from each parent
divergent evolution when a single species evolves into two or more separate species with differing characteristics due to geographic differences and selection pressures
ecological succession in an area of virtually no life, a biological community is established
ecosystem a community and it’s surrounding physical environment - involves all organisms in the area as well as the abiotic factors that they interact with
ectothermic animals animals that must regulate its body temperature by using environmental energy and behavioral adaptations
electron microscope a microscope that shoots an electron beam through a specimen
embryonic induction when the presence of one tissue influences how/when others develop
endergonic reactions a chemical reaction that is nonspontaneous in which free energy is taken in from surroundings
endocytosis the formation of intracellular vesicles by way of cellular uptake of macromolecules by regions of the membrane that surround substances and pinch them off
endomembrane system the collection of membranes inside and around a eukaryotic cell
endoplasmic reticulum membranous network found in eukaryotic cells that is composed of rough (ribosome-studded) and smooth (ribosome-free) regions
endothermic animals animals that maintain body temperature by using metabolic energy
energy coupling the use of energy released from an exergonic reaction to drive an endergonic reaction
enthalpy total energy of a thermodynamic system
entropy a measure of disorder or randomness in a community
epidermis the outer layer of animals; the dermal tissue system in plants
estivation time of slow metabolism and inactivity which allows for survival during long periods of time with little water supplies and elevated temperatures
ethylene gaseous plant hormone that is used in fruit ripening, growth, leaf abcission, and aging
eukaryotes an organisms whose cells contain DNA enclosed in a cell nucleus and contains membrane-bound organelles
exergonic reactions spontaneous reaction in which there is a release of free energy
exocytosis macromolecules are secreted by the fusion of vesicles with the plasma membrane
facilitated diffusion passage of molecules across a biological membrane down their concentration gradient by being bound to a specific carrier protein
feedback inhibition when the end result of a metabolic pathway acts as an inhibitor of an enzyme that is a party of the pathway
fermentation catabolic process that produced a limited amount of ATP from glucose and produces end products such as ethyl alcohol or lactic acid
flagella cellular appendage specialized for movement
fluid mosaic model a model for the membrane of a cell developed by S.J. Singer and Garth Nicolson in 1972
food chain how food is transferred from one trophic level to another, starting with producers
food vacuole membrane bound organelle in which ingested food is digested
food web the feeding relationships between organisms in an ecosystem
fruit ripening regarded as a senescence or ageing process for fruits in which they become more edible
G proteins proteins that bind to GTP and relay signals from the membrane signal receptor to other signal-transduction proteins inside the cell
gastrovascular cavities the central digestive compartment with a singular opening that functions as both mouth and anus
gibberellin related plant hormones that stimulate fruit development, trigger the germination of seeds and breaking of bud dormancy, and stimulate growth in the stem and leaves
gills an extension on the surface of the body of many aquatic animals, intended for gas exchange
glucagon a peptide hormone that raises blood glucose levels after being secreted by the pancreatic endocrine cells
glycolipid similar to fats in their structure, however they contain a carbohydrate chain rather than a fatty acid that is attached to the third carbon of the glycerol molecule; make up the plasma membrane and organelle membranes
glycolysis the process by which glucose is split into pyruvate
glycoprotein carbohydrates are covalently attached to a protein
Golgi apparatus organelle in eukaryotic cells that consists of stacks of membranous sacs that function to modify, store, and transport products that come from the endoplasmic reticulum
guard cells plant cell of the epidermis that forms the boundaries of the stomata
halophiles an organisms that grows in saline conditions
haploid cell a cell in which only one set of chromosomes exists
heat of vaporization the amount of heat required to change a set amount of liquid into a gaseous solution
heterotrophs an organisms that eats other organisms or their by-products to obtain organic food molecules
hibernation state in which metabolism decreases, the heart and respiratory systems slow down, and body temperature is maintained at a low level during periods of cold weather and reduced food availability to aid in survival
high specific heat capacity the amount of energy it takes to increase the temperature of 1 gram of a substance by 1 degree Celcius
homeostasis physiological condition of the body in which everything is in a steady-state
homeotic genes group of genes that controls the layout of the body for animals by controlling the developmental fate of groups of certain cells
hormone type of circulating chemical signal that are formed in specialized cells, travel throughout the body, and interact with various parts of the organism by binding to target cells
humoral immunity fights viruses and bacteria with antibodies that circulate throughout the blood plasma and lymph
hydrogen bonding weak chemical bond that forms when the positive hydrogen atom is attracted to the negative atom of another molecule
hypertonic a solution in which there is a greater solute concentration than another solution
hypothalamus maintains homeostasis as part of the vertebrate forebrain
hypotonic a solution in which there is a lesser solution concentration than another solution
insulin receptor a transmembrane receptor that is activated by insulin, IGF-I, IGF-II and belongs to the large class of tyrosine kinase receptors
integral proteins assembly of proteins that is firmly anchored in the plasma mebrane due to its hydrophobic domains that interact with the phospholipids of the membrane
interspecific competition when organisms from different species compete for the same resource in a singular ecosystem
intestine in vertebrates, the lower part of the alimentary canal that goes from the end of the stomach to the anus; in invertebrates, the whole alimentary canal from mouth to anus
invasive species when a non-native species disrupts and replaces a native species of a particular area
ion pump a vacuum pump that removes gas
isotonic solutions in which there are equal solute concentrations
kidneys organs that regulate the balance of water and solutes in the blood and excretes nitrogenous wastes
kinesis the change, in response to a stimulus, in activity rate
Krebs cycle the second major stage in cellular respiration that occurs in the mitochondrion involving a chemical cycle that completes the breakdown of glucose to carbon dioxide
lactic acid fermentation process by which glucose, fructose, and sucrose are converted into energy and metabolic lactate
labor onset during childbirth progressive cervical effacement and dilation that result from regular and painful uterine contractions
large central vacuole in plant cells; used to retain water and help the plant function and prevent it from drying out
ligand a molecule that binds to another molecule, usually larger.
light microscope a microscope that uses refracted light.
lungs invaginated respiratory surfaces that connect to the atmosphere by narrow tubes
lysosome membrane bound sac of hydrolytic enzymes in the cytoplasm of eukaryotes
meiosis two stage type of cell division that results in gametes with half the chromosome number of the original cell
membrane sheetlike structure that acts as a boundary, lining, or partition for an organism
metabolism the entirety of an organism’s chemical processes, including catabolic and anabolic pathways
microRNAs non-coding RNA molecule found in both plants and animals that is used in transcriptional and post-transcriptional gene regulation
microvilli fine, fingerlike projections of the epithelial cells of the small intestine that increases surface area
mitochondrion organelle in eukaryotic cells that is the site for cellular respiration to occur
mitosis nuclear division divided into five stages - prophase, prometaphase, metaphase, anaphase, and telophase - that conserves chromosome number by allocating equal numbers of replicated chromosomes to each of the daughter cells
mutualism symbiotic relationship in which both the host and the symbiont benefit from the other
natural disasters major adverse event that results from natural processes of the Earth and can cause life loss and property damage
necrosis the death of cells in an organ or tissue as a consequence of disease, injury, or failure of the blood supply
negative feedback when a change in a physiological variable triggers a response that counteracts the initial fluctuation
nephridium tubular excretory structure found in invertebrates
net primary productivity represents the storage of chemical energy available to consumers within an ecosystem
niche sum total of how an organism utilizes the biotic and abiotic resources of its environment
non-halophiles organisms that do not thrive in the salty conditions that is favored by halophiles
noncyclic photophosphorylation noncyclic electron flow that results in the production of ATP
nuclear envelope membrane in eukaryotic cells that encloses the nucleus, which separates it from the cytoplasm
nuclear pore complex openings in a nuclear membrane which allows for the passage of molecules between the nucleus and the surrounding cytoplasm
nucleoid dense region of DNA within a prokaryotic cell
nucleoid region the region consisting of a mass of DNA
nucleoside organic molecule consisting of a nitrogenous base joined to a five carbon sugar
nucleus an atom’s central core that contains chromosomes
oligosaccharides saccharide polymer consisting of a small number of simple sugars
one way digestive systems undigested and digested food are passed through the same opening
osmoconformer organism whose body fluid solute concentration is the same as the solute concentration of the medium in which the organism lives
osmoregulator organism that can regulate the solutes of its body fluid at a higher or lower concentration than the concentration of solutes in the medium its surrounded in
osmosis diffusion of water across a selectively permeable membrane
oxidative phosphorylation energy derived from the redox reactions of the electron transport chain produces ATP
oxytocin hormone that acts primarily as a neuromodulator in the brain
passive transport diffusion of a substance across a biological membrane
pectins heteropolysaccharide found in the primary cell walls of terrestrial plants
peptidoglycan type of polymer in bacterial cell walls that contain modified sugars that are cross-linked by short polypeptides
perennial plant that lives for many years
periodic disturbances temporary change in average environmental conditions that causes pronounced changes in the ecosystem
peripheral proteins adhere only temporarily to the biological membrane with which they are associated
phagocytosis a type of endocytosis which involves large, particulate substances v
pheromones chemical signal that functions in communication between animals and influences physiology and behavior
phospholipid molecules that make up the inner bilayer of biological membranes which have polar, hydrophilic heads and nonpolar, hydrophobic tails
phospholipid bilayer thin polar membrane made of two layers of lipid molecules that form a continuous barrier around cells
phosphorylation cascade a sequence of events where one enzyme phosphorylates another causing a chain reaction
photoperiodism physiological response to day length
photophosphorylation process of generating ATP from ADP/phosphate by a proton motive force generated by the thylakoid membrane of the chloroplast
photosynthesis conversion of light energy to chemical energy that is stored in glucose or other organic compounds
photosynthetic relating to, using, or formed by photosynthesis
phototropism the growth of a plant shoot toward or away from light
phylogeny a species or group of related species evolutionary history
pinocytosis a type of endocytosis in which the cell ingests extracellular fluid and the solutes that have dissolved within it
plasma membrane membrane that acts as a selective barrier, which calls for the regulation of the cells chemical composition
polarization waves of light or other radiation are restriction in direction of vibration
pollination placement of pollen onto the stigma of a carpel by wind or animal carriers which acts as a prerequisite to fertilization
population group of individuals of one species that live in a particular area
positive feedback physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change
predation interaction between species in which one eats the other
predator an organism that eats other organisms that are living
prey organisms that are eaten by other organisms
primary consumers organism in the trophic level of an ecosystem that eats plants or algae
primary producers collectively makes up the trophic level of an ecosystem that ultimately supports all other levels
primary succession ecological succession that occurs in an area where there were originally no organisms present
prokaryotic cell cell that lacks a membrane bound nucleus and organelles
protein kinase enzyme that transfers phosphate groups from ATP to a protein
protein synthesis process by which cells make proteins
pyruvate oxidation source of Acetyl-CoA molecules for the citric acid cycle
quorum sensing system of stimulus and response correlated to population density
receptor specific protein molecule whose shape fits that of a specific molecular messenger
receptor-mediated endocytosis movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in
regeneration process of renewal, restoration, and growth that makes genomes, cells, organs, organisms, and ecosystems resilient to natural fluctuations or events that cause damage
resolution return to normal structure and function
resource partitioning division of environmental resources by coexisting species population such that the niche of each species differs by one or more significant factors from the niches of all coexisting species populations
ribosome cell organelle that functions as the site of protein synthesis in the cytoplasm
RNA ribonucleic acid; type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous base adenine, cytosine, guanine, and uracil
RNA polymerase enzyme that links together the growing chain of ribonucleotides during transcription
root descending axis of a plant, usually below ground to anchor the plant and tkae up water and dissolved minerals
root cap cone of cells at the tip of a plant root that protects the apical meristem
root hairs projection growing just behind the root tips of plants, which increase the surface area for the absorption of water and minerals
rough endoplasmic reticulum the portion of the endoplasmic reticulum that is studded with ribosomes
rubisco enzyme that catalyzes the first step of the Calvin cycle
secondary consumers member of the trophic level of an ecosystem consisting of carnivores that eat herbivores
secondary succession succession that occurs where an existing community has been cleared by some kind of disturbance
selectively permeable allows some substances to pass through easier than others
septum partition that divides a structure into compartments
sexual reproduction reproduction in which two parents give rise to offspring that have combinations of genes inherited by each of the two parents
sexual selection selection based on variation in secondary sex characteristic
smooth endoplasmic reticulum portion of the endoplasmic reticulum that is free of ribosomes
solute substance that is dissolved in a solution
solution homogeneous liquid mixture of two or more substances
solvent the dissolving agent of a solution
somatic cells any cell in an organism except for sperm or egg cells
speciation origin of a new species in the process of evolution
stomach internal organ in which the first part of digestion occurs
stomata microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and interior of the plant
tertiary consumers member of a trophic level of an ecosystem of carnivores that eat mainly other carnivores
thermoregulation maintenance of internal temperature within a tolerable range
transcription factors regulatory protein that binds to DNA and stimulates the transcription of genes
transpiration evaporative loss of water from a plant
trophic levels division of species in an ecosystem on the basis of their main nutritional source
universal solvent water - substance that dissolves most chemicals
vacuole a small cavity in the cytoplasm of a cell that is membrane-bound and usually is filled with fluid of some kind
vegetative reproduction the asexual means of cloning plants
ventricle a chamber of the heart that pumps blood out of the heart and into the blood stream
vesicle a membranous sac inside a cell
villi small projections on the inner lining of the small intestine that increases the surface area of the organ
adenine nucleobase that has roles in respiration, ATP synthesis, and protein synthesis as a chemical component of both DNA and RNA
allele an alternative version of a gene that creates phenotypic effects on the organism
alternative splicing process during gene expression that leads to a single gene providing the coding for more than one protein
amino acid derivative molecule that is generated using an amino acid as a starting point
anaphase a stage of cell division when the chromosomes move away from one another.
aneuploidy when at least one chromosome is present in extra copies or are lacking in number
apoptosis programmed cell death
autocrine signaling cell secretes a hormone or chemical messenger that binds to autocrine receptors on the same cell, leading to changes
cancer when cells replicate too fast in the body
cell cycle an ordered sequence of events during a eukaryotic cell’s lifetime from its origin to the eventual division of a parent cell
cellular differentiation when a less specialized cell becomes more specialized
cell division when one cell seperates into two different cells
cell plate a double membrane along the middle of a plant cell during division and between the membranes the new cell wall is formed in cytokinesis
centrioles an organelle near the nucleus of the cell in animals they occur in pairs.
centromere the central region that joins sister chromatids
chaperonins can unfold proteins so they can be transported
chiasma a microscopically visible region that represents homologous chromatids which have already exchanged genetic material during the process of crossing over
chromosome threadlike structure in the nucleus that contains DNA
chromosomal mutations any event that changes genetic structure
Circadian rhythms physiological cycle of about 24 hours that persists even in the absences of external cues
cleavage furrow a shallow recess in the cell’s surface near the older metaphase plate that will lead to cleavage in an animal cell
codominance when the phenotypes of each allele are exhibited in a heterozygous individual
conjugation the direct DNA transfer between cells in prokaryotes
control elements region of DNA that allows the regulation of gene expression by the binding of transcription factors
crossing over the exchange of genes and genetic material between homologous structures.
crossover frequency the frequency in which crossing over occurs
cyclin dependent kinase involved in the regulation of the cell cycle
cytokinesis the formation of two daughter cells immediately after mitosis that is signaled by the division of the cytoplasm
cytosine one of the four main nitrogenous bases found in DNA and RNA
deletions mutational loss of a nucleotide from a gene
deoxyribose DNA’s sugar component that has one less hydroxyl group than ribose
diploid a cell consisting of two sets of chromosomes
DNA a molecule (deoxyribonucleic acid) that encodes genetic instructions for development and functional processes of living organisms and sometimes viruses
DNA ligase enzyme that is responsible for catalyzing the covalent bonding of the 3’ and 5’ ends
DNA methylation process by which an additional methyl group is added to the cytosine or adenine DNA nucleotides; this alters the expression of genes in cells as they divide and differentiate
DNA polymerase enzyme that catalyzes DNA elongation at the replication fork through the adding on of nucleotides to the already existing chain
DNA replication process in all living organisms where DNA is copied and replicated that provides the basis of biological inheritance
double helix the form of DNA with two adjacent strands that are wound in a spiralling shape
epistasis one gene changes the effects of a phenotype of another independently inherited gene
euchromatin an unraveled form of chromatin in eukaryotes that is readily available for transcription
fertilization the union of male sperm and female eggs
G protein linked receptors receptors that are used to sense molecules outside the cell and activate signal transduction pathways which lead to a cellular response
gene mutations an alteration in the DNA of a particular gene which leads to genetic diversity
germination resumption of growth or the development from seed to spore
Gregor Mendel scientist who demonstrated that the inheritance of traits in pea plants followed certain patterns which are now called the laws of Mendelian inheritance
guanine one of the four main nucleobases in the nucleic acids of RNA and DNA
helicase an enzyme that is responsible for unwinding DNA’s double helix at the replication forks on the strand
hemizygous an organism with only one part of a chromosome pair instead of the usual two
heterochromatin eukaryotic chromatin that is visible during interphase with a light microscope because it is so tightly compacted
heterozygous the state of having two different alleles for a certain gene
histone a protein that has a high amount of amino acids with a positive charge and binds to the DNA which has a negative charge
histone acetylation the process of the amino acids of histones being attached to acetyl groups
homeotic genes genes that are responsible for causing the development in plants and animals of certain structures
homologous chromosomes chromosome pairs that are the same length, have the same position on the centromere, and genes for the same characteristic at the loci
homozygous state of having two identical alleles for a certain gene
hydrogen bonds a weak chemical bond that is formed when a positively charged hydrogen atom in one molecule is attracted to the slightly negative charge in another atom
incomplete dominance when a heterozygote’s phenotype is intermediate to that of either homozygous individual
independent assortment Mendel’s second law which states each allele pair divides independently of each other during the formation of a gamete
inducible operon may be either negative or positive, depending on the ability of proteins to bind to the DNA
insertions a type of mutation in which nucleotide pairs are added to a gene
interphase a part in the cell cycle during which the cell is not dividing but chromosomes and organelles are being duplicated and the cell grows in size
intron a sequence in a eukaryotic gene that is noncoding and intervening
inversions when a chromosome is reattached to the fragment from which it came in reverse order
Jacob and Manod first researches to discover an operon system
kinetochore a region on the centromere that joins the mitotic spindle to sister chromatids
lagging strand DNA strand that is noncontinuous and elongates away from the replication fork
leading strand a continuous strand of DNA that is synthesized from the 5’ end to the 3’ end
ligand molecule that specifically binds to another at the receptor site
ligand gated ion channels a pore composed of proteins in the membrane of a cell that either opens or closes based upon a response to a chemical signal
linked genes genes that are close enough together that they are inherited together for the most part
linked traits a genetic characteristic in an organism that results from genes being located on certain chromosomes
lysogenic cycle a replication cycle of a phage during which the genome of the virus is incorporated into the host without killing it
lytic cycle a replication cycle of a phage during which the phage is released through the death of the host
macrophages a phagocytic cell that in the innate immunity system destroys microbes
meiosis a type of cell division that takes place in organisms that reproduce sexually that leads to cell with half of the chromosomes of the original cell
melatonin hormone that is secreted in the pineal gland and that regulates bodily functions that relate to day length seasonally
membrane potential the difference in charge between the cytoplasm and extracellular fluid of a cell
Mendelian genetics genetics based upon the work and theories of Gregor Mendel
messenger molecules a molecule that relates information after it is received and interpreted
migration movement of organisms from one geographical location to another
mitosis a means of division in eukaryotic cells
multiple alleles when there are more than two possible alleles and each individual still has two of the possible alleles.
mutations a change in a gene’s structure that results in a variant form being created, which may be transmitted to future generations through reproductive processes
nondisjunction a type of error in the processes of meiosis or mitosis that results from members of homologous chromosomes failing to move apart in the proper manner
nucleic acid a polymer of nucleotide monomers
nucleotide a five carbon sugar that is bonded to a nitrogenous base and phosphate group covalently
Okazaki fragments a smaller segment of DNA that is synthesized during DNA replication and makes up the lagging strand
operator binding spot on the DNA next to the promoter
operons regulated clusters of genes that have related functions
paracrine control form of bioregulation where one cell influences the activity of another adjacent cell by releasing chemicals into the tissue to act on that specific cell
peptides a short amino acid chain that is joined together through amino bonds
phagocytes a cell that has the capability to destroy substances by ingesting them
phenotype the observable, physical characteristics of an organism which is a result of the environment and genotype interacting over time
pheromones a small chemical that has an active role in communication in plants and animals and which influences the behavior and physiology of animals
phloem a vascular tissue in plants that transports materials throughout the plant
photoperiodism a physiological response to the lengths of day and night
phototropins proteins that regulate phototropism in taller plants
phototropism the growth of a plant towards/away from a light source
pilus in prokaryotes a hairlike appendage that is used to adhere to objects/substances and uses in the transfer of DNA in conjugation
plasmodesmata a thin cytoplasmic thread that goes through the cell walls of plant cells adjacent to one another to allow communication
point mutations an alteration in a gene at one nucleotide pair
poly A tail a modified end of the 3’ end in an RNA molecule that has an addition of adenine nucleotides
polygenetic inheritance the effect of at least two gene loci on one phenotypic character
polygenic traits any trait that is controlled by groups of non-allelic genes
polyploidy an alteration in an organism's chromosomes where the organisms has more than two full sets of chromosomes
positive feedback loop a mechanism of control where a variable change directly causes other mechanisms to amplify that change
post transcriptional regulation gene expression that is regulated at the RNA level and occurs between a gene’s transcription and translation
promoter a certain sequence of nucleotides in a strand of DNA that binds with RNA polymerase and signals where RNA transcription starts
proteasome an extremely large protein complex that identifies and eliminates proteins that ubiquitin has labeled to be eliminated
protein hormones proteins that in living animals have endocrine functions
purine one of the two types of nitrogenous bases that exist in nucleotides; adenine and guanine are the purines
pyrimidine one of the two types of nitrogenous bases that exist in nucleotides; cytosine, thymine, and uracil are pyrimidines
random fertilization the fact that one of almost infinitely many kinds of sperm has the capability to fertilize an egg
receptor proteins proteins in either the membrane, cytoplasm, or nucleus of the cell to which certain signaling molecules will bind
regulatory T cells cells that have vital roles in the immune system, maintain self-antigen tolerance, and also help regulate autoimmune responses
replication fork a region on a replicating DNA molecule that resembles a Y in shape where new strands will grow
repressible operon an operon is repressible if excess amounts of the end product leads to the stopping of the transcription of the genes
repressor any protein that inhibits the transcription of a gene
ribose the sugar component of an RNA molecule
RNA ribonucleic acid; type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous base adenine, cytosine, guanine, and uracil
second messenger a watersoluble molecule/ion that carries a signal to the interior of a cell in a response to a signal received by a receptor protein
semi-conservative a kind of DNA replication during which the double helix is composed of one older strand and one new strand
sex linkage the phenotypic expression of any allele that is related to the sex of the organism
signal cascades a series of reactions during which one reaction’s products are consumed by the next reaction
single strand binding protein binds to the regions of DNA that are single-stranded in order to prevent annealing, which protects the single strand of DNA from becoming consumed by nucleases
signal transduction pathways a type of mechanism that links a stimulus to a certain response from the cell
splicing process by which introns are removed and exons are joined for eukaryotic messenger RNA so it can be utilized to produce a correct protein later on in translation
synapsis when homologous chromosomes are replicated and paired during prophase of meiosis
synaptic signaling a kind of cell communication across the synapses in the nervous system
T cells a type of lymphocyte that develops in the thymus and is responsible for cell-mediated immunity
target cell a cell that has receptors for a certain drug, hormone, or other type of signalling molecule
telomere the end of a chromosome whose DNA has a simple repeating unit with a single-stranded end
thymine one of the four nucleobases in DNA, is a pyrimidine nucleobase
transduction converting a signal from outside of the cell into a form that can lead to a certain response from that cell
transformation an alteration in the genotype and phenotype of an organism due to the cell assimilating external DNA
translocation a deviation in the structure of chromosomes that happens as a result of nonhomologous chromosomes attaching to chromosome fragments
ubiquitin a protein in eukaryotic cells that joins with other proteins and makes them now vulnerable to destruction by the cell
uracil one of the four nucleobases in RNA nucleic acid; is a pyrimidine
Walter Sutton geneticist who theorized that Mendel’s laws of inheritance could also be applied on the chromosomal level as well
active site part of an enzyme that binds to the substrate by way of chemical bonds
alimentary canal passage by which food enters the body and then solid wastes are expelled
allosteric site receptor site on an enzyme remote from the active site; the molecules bind to the site and change the shape of the active site changing its reception of the substrate
alveoli air sacs that are on the gas exchange surface of the lungs
amino acid serve as monomers of proteins possessing both carboxyl and amino groups
amino groups group that consists of one nitrogen atom bonded to two hydrogen atoms
atom basic unit of matter with a dense central nucleus
atomic mass the mass of an atom
atomic number the number of protons in the nucleus of an atom
atrium chamber of the heart that receives blood returning from the rest of the body
carbohydrates a sugar or one of it’s dimers or polymers (monosaccharides, disaccharides, polysaccharides)
cell theory all living things are composed of cells
chloroplast organelle in plants that absorbs light from the sun and uses that energy to drive the synthesis of organic compounds from carbon dioxide to water
cholesterol steroid that forms an essential component of animal cell membranes and is the precursor for the synthesis of other important steroids
chromosome compaction occurs during mitosis and meiosis, resulting in the four arm structure
cilium short cellular appendage specialized for locomotion
coenzymes serves as a cofactor
cofactors nonprotein molecule that is required for an enzyme to carry out its proper function
competitive inhibition substance that reduces the enzyme activity by mimicking the structure of the substrate and entering the active site
communities consists of a population
commensalism a relationship where one population benefits and the other populations is not affected.
competitive exclusion the principle that two populations are negatively affected by their relationship.
covalent bond chemical bond by the sharing of one or more pairs of electrons
cytoskeleton a series of microtubules, microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve for transport and mechanical function
cytosol semi-fluid portion of the cytoplasm
differential gene expression the expression of different sets of genes by cells with the same genome
Disaccharides a double sugar composed of two monosaccharides joined together by dehydration synthesis
electrons subatomic particle with a negative charge
energy levels states of potential energy for electrons in an atom
extracellular matrix proteins and polysaccharides in which animal tissue cell are embedded
fatty acid carbon chain of carboxylic acid
feedback inhibition metabolic control in which the end product of a metabolic pathway acts as the inhibitor to an enzyme
flagellum long cellular appendage specialized for locomotion
flame cell the organ of excretion in flatworms
food chain shows one way diagram of a feeding relationship inside of a community.
food web displays all the feeding habits within a community.
glycolipids lipid covalently attached to a carbohydrate
golgi apparatus organelle in eukaryotic cells comprised of sacs that modify, store, and route products
hormone circulating chemical signals formed in specialized cells, travel in body fluids and act on certain target cells to change how they function
hydrogen bond weak chemical bond formed when a positive hydrogen atom of a polar covalent bond is attracted to a negative atom of a polar covalent bond of another molecule
hydrophilic an affinity for water
hydrophobic an aversion to water
inducible operons used to produce proteins under certain specific conditions
intercellular junctions the connections between one cell and another
invasive species a species that takes hold of an environmental area outside of its native range
ionic bond chemical bond due to the attraction of oppositely charged ions
isotope atomic form of an element
keystone species species that is not abundant but exerts strong control on community strucutre by its ecological role or niche
limiting factor a factor that controls a process like evolution or natural selection
logistic growth growth rates that are controlled by internal and external factors
lysosome membranous sac of hydrolytic enzymes found in the cytoplasm of eukaryotic cells
malpighian tubule excretory organ of insects that empties into the digestive tract, removes nitrogenous wastes from the hemolymph and has a role in osmoregulation
mitochondrion site of cellular respiration in eukaryotic cells
monosaccharides simplest carbohydrate, active alone or can serve as a monomer for disaccharides and polysaccharides
mRNA messenger RNA - a type of RNA that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein
mutualism relationship where both populations benefit from the relationship at hand.
nephridia tubule opening to the exterior that serves as an organ of excretion/osmoregulation
neuron a nerve cell
neurotransmitter chemical messenger that diffuses across the synaptic cleft and binds to and stimulates the postsynaptic cell
neutrons electrically neutral particle found in the nucleus of an atom
niche sum total of a species’ use of the abiotic and biotic resources in their surrounding environment
nonpolar covalent bond type of covalent bond in which electrons are shared equally between two atoms
nucleic acid polymer consisting of nucleotide monomers serving as a blueprint for proteins
nucleolus specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes
nucleotide building block of a nucleic acid consisting of a nitrogenous base and a phosphate group
octet rule principle that bonded atoms share their eight outer electrons
operator sequence of nucleotides near the start f an operon to which an active repressor can attach preventing RNA polymerase from attaching to the promoter and transcribing genes of the operon
organ specialized center of body function composed of tissues
organelle one of several formed bodies with specialized functions in the cytoplasm of eukaryotic cells
parasitism a relationship where the parasite benefits by gaining nutrients from its host, which in turn, is negatively affected.
peptide bond the covalent bond between two amino acid units through dehydration reactions
peroxisome microbody that contains enzymes used to transfer hydrogen from various substrates to oxygen, producing and degrading hydrogen peroxide
polar covalent bond covalent bond between atoms that have different electronegativities
polysaccharides polymer of up to over a thousand monosaccharides formed due to dehydration reactions
predation relationship where the predator benefits by consuming the prey (which is negatively affected).
primary consumers herbivores animals that feed on the producers.
producers autotrophic plants within a community.
protons positive electrons
purine one of two nitrogenous bases found in nucleotides - Adenine and Guanine
pyrimidine one of two nitrogenous bases found in nucleotides - Cytosine, Thymine, Uracil
quadrat parts of a habitat, usually one square mile, that are chosen for samples of an experiment.
R selection the selection for the combination of traits in an organism
radioactive isotopes an isotope that is unstable, the nucleus decays spontaneously, giving off detectable particles and energy
rate of reaction how fast a reaction occurs affected by temperature and pH.
repressor protein that suppresses the transcription of a gene
resilience the ability of a strained body to retain its shape
ribosomes cell organelle constructed in the nucleolus and function as the site of protein synthesis in the cytoplasm
saprophyte an organism that lives off of the dead
secondary consumers carnivorous animals that eat the herbivores.
species diversity the collection of different species presented in a collection of individuals
spiracles arthropods openings that open into the trachea
steroid type of lipid characterized by a carbon skeleton consisting of four rings and various functional groups
substrate reactant on which an enzyme works
substrate feeder organism that lives in or on its food source
survivorship curve a graph that displays the number of individuals surviving at a specific age for a species.
ten percent rule when you only retain 10% of the energy when you consume an organism
tertiary consumers the higher order of carnivores that eat the secondary consumers.
triglyceride formed from glycerol and three fatty acid groups, constituting natural fats and oils
threatened species a species that is at risk of extinction.
trophic level the levels of an ecosystem
urbanization when an environment undergoes changes that include communites of houses ect being built
vacuole membrane enclosed sac containing a variety of substances for reproduction, growth, and development
valence electrons an electron in the outermost electron shell
Van der Waal interaction weak attractions between molecules that are brought about by localized charge fluctuations
ventricle heart chamber that pumps blood out
vesicle sac made of membrane inside of cells
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