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| 13949086249 | adaptation | characteristics of organisms that enhance their survival and reproduction in specific environments | 0 | |
| 13949102676 | adaptative radiation | emergence of numerous species from single common ancestor introduced into an environment | 1 | |
| 13949105548 | allele | different forms of a gene | 2 | |
| 13949108015 | allopatric speciation | the formation of new species in populations that are geographically isolated from one another | 3 | |
| 13949113534 | analogous structures | similarities among unrelated species that result from convergent evolution | 4 | |
| 13949117534 | antibiotic resistance | the ability of bacteria to withstand the effects of an antibiotic | 5 | |
| 13949117535 | artificial selection | selective breeding of plants and animals to promote the occurrence of desirable traits in offspring | 6 | |
| 13949119906 | bottleneck effect | a reduction in the genetic diversity of a population caused by a reduction in its size | 7 | |
| 13949122875 | cladogram | a branching diagram showing the cladistic relationship between a number of species | 8 | |
| 13949124929 | clade | group of species that includes an ancestral species and all its descendants | 9 | |
| 13949127163 | common ancestor | the most recent ancestral form or species from which two different species evolved | 10 | |
| 13949131798 | convergent evolution | the independent evolution of similar features in different lineages | 11 | |
| 13949134774 | directional selection | occurs when natural selection favors one of the extreme variations of a trait |  | 12 |
| 13949137805 | disruptive selection | form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle |  | 13 |
| 13949145703 | divergent evolution | when two or more species sharing a common ancestor become more different over time | 14 | |
| 13949145704 | emigration | movement of individuals out of an area | 15 | |
| 13949149512 | evolution | descent with modification, change in genetic composition of a population from generation to generation | 16 | |
| 13949154590 | fertility | the production of offspring within a population | 17 | |
| 13949157155 | founder effect | change in allele frequencies as a result of the migration of a small subgroup of a population | 18 | |
| 13949159014 | gene flow | movement of alleles from one population to another | 19 | |
| 13949162486 | gene pool | all the genes, including all the different alleles for each gene, that are present in a population at any one time | 20 | |
| 13949164877 | genetic drift | random change in allele frequencies that occurs in small populations | 21 | |
| 13949167395 | homologous structures | similar structures that related species have inherited from a common ancestor | 22 | |
| 13949170374 | hybrid | offspring that result from an interspecific mating | 23 | |
| 13949188237 | immigration | migration to a new location | 24 | |
| 13949190802 | isolation types | pre-zygotic includes sexual, geographic, ecological, behavioral, temporal, and mechanical & post-zygotic includes hybrid sterility, hybrid inviability, zygote mortality | 25 | |
| 13949199327 | limited resources | the condition of there not being enough resources to fulfill all wants and needs | 26 | |
| 13949202616 | mutation | a random error in gene replication that leads to a change | 27 | |
| 13949205985 | natural selection | individuals with certain inherited traits leave more offspring than individuals with other traits | 28 | |
| 13949210438 | outgroup | generally, any group that one does not belong to | 29 | |
| 13949212697 | phenotype | physical characteristics of an organism | 30 | |
| 13949218456 | phylogenetic tree | diagram showing evolutionary relationships of organisms with a common ancestor; resembles a tree | 31 | |
| 13949218457 | population | group of individuals of the same species that live in the same area | 32 | |
| 13949222000 | protobiont | a collection of abiotically produced molecules surrounded by a membrane or membrane-like structure | 33 | |
| 13949224133 | random mating | no selective mating in which animals choose mate depending on phenotype | 34 | |
| 13949227197 | reproductive isolation | separation of a species or population so that they no longer interbreed and evolve into two separate species | 35 | |
| 13949234612 | serial endosymbiosis | supposes that mitochondria evolved before plastids through a sequence of endosymbiotic events | 36 | |
| 13949236893 | sexual selection | individuals with certain inherited characteristics are more likely than other individuals to obtain mates | 37 | |
| 13949243198 | speciation | the formation of new and distinct species in the course of evolution | 38 | |
| 13949245571 | species | a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding | 39 | |
| 13949245572 | stabilizing selection | form of natural selection by which the center of the curve remains in its current position; occurs when individuals near the center of a distribution curve have higher fitness than individuals at either end |  | 40 |
| 13949251076 | sterility | the inability to reproduce | 41 | |
| 13949251077 | sympatric speciation | the formation of new species in populations that live in the same geographic area | 42 | |
| 13949256328 | variation | differences in physical traits of an individual from the group to which it belongs | 43 | |
| 13949258342 | vestigial organs | organ that serves no useful function in an organism | 44 | |
| 13949261001 | viability | ability to exist | 45 | |
| 13949312814 | anabolic reactions | build up large chemicals and require energy |  | 46 |
| 13949320270 | apomixis | asexual production of seeds | 47 | |
| 13949324792 | asexual reproduction | process by which a single parent reproduces by itself | 48 | |
| 13949327561 | adenosine triphosphate | atp | 49 | |
| 13949330436 | atp synthase | large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP | 50 | |
| 13949334281 | binary fission | a form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size |  | 51 |
| 13949338743 | biotic | living | 52 | |
| 13949338744 | budding | a form of asexual reproduction of yeast in which a new cell grows out of the body of a parent | 53 | |
| 13949340919 | calvin cycle | reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars (light-independent) | 54 | |
| 13949349507 | catabolic reactions | break down large chemicals and release energy |  | 55 |
| 13949352935 | chemiosmosis | a process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme | 56 | |
| 13949355682 | chloroplast | organelle found in cells of plants that captures the energy from sunlight and converts it into chemical energy | 57 | |
| 13949358592 | community | all the different populations that live together in an area | 58 | |
| 13949360577 | competitive inhibitor | a substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics | 59 | |
| 13949366587 | concentration gradient | difference in the concentration of a substance from one location to another | 60 | |
| 13949375311 | consumer | organism that obtains energy and nutrients by feeding on other organisms | 61 | |
| 13949379499 | cooperativity | allosteric regulation where a shape change in one subunit of a protein caused by substrate binding is transmitted to all the other subunits, facilitating binding of additional substrate molecules to those subunits | 62 | |
| 13949400355 | courtship behavior | behavior that allows males and females of the same species to recognize each other and prepare to mate | 63 | |
| 13949405777 | cryptic coloration | camouflage that makes a potential prey difficult to spot against its background | 64 | |
| 13949408730 | cuticle | waxy covering on the surface of stems and leaves that acts as an adaptation to prevent desiccation | 65 | |
| 13949416548 | photophosphorylation | process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis | 66 | |
| 13949422286 | cytoskeleton | network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement | 67 | |
| 13949427593 | diffusion | movement of molecules from an area of higher concentration to an area of lower concentration | 68 | |
| 13949441368 | ecosystem | biological community of interacting organisms and their physical environment | 69 | |
| 13949443477 | endergonic reaction | non-spontaneous chemical reaction in which free energy is absorbed from the surroundings | 70 | |
| 13949453724 | energy coupling | the use of an exergonic process to drive an endergonic one | 71 | |
| 13949455892 | enthalpy | the heat content of a system | 72 | |
| 13949455893 | entropy | a measure of the disorder of a system | 73 | |
| 13949457739 | exergonic reaction | spontaneous chemical reaction in which there is a net release of free energy | 74 | |
| 13949465502 | facilitated diffusion | process of diffusion in which molecules pass across the membrane through cell membrane channels | 75 | |
| 13949468261 | feedback inhibition | a method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway | 76 | |
| 13949474448 | fermentation | catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid |  | 77 |
| 13949481604 | g protein | a protein that binds the energy-rich molecule GTP | 78 | |
| 13949481605 | glycolysis | the breakdown of glucose by enzymes, releasing energy and pyruvic acid | 79 | |
| 13949486150 | golgi apparatus | stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum |  | 80 |
| 13949510250 | homeostasis | process by which organisms maintain a relatively stable internal environment | 81 | |
| 13949510251 | hypertonic | solution with greater concentration of solutes (water leaving) |  | 82 |
| 13949520234 | hypotonic | solution with lesser concentration of solutes (water entering) |  | 83 |
| 13949526499 | isotonic | when the concentration of two solutions is the same |  | 84 |
| 13949530352 | krebs cycle (citric acid cycle) | second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions | 85 | |
| 13949533014 | lysosome | an organelle containing digestive enzymes | 86 | |
| 13949533015 | metabolism | all of the chemical reactions that occur within an organism | 87 | |
| 13949542275 | meiosis | a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell |  | 88 |
| 13949555474 | mitochondria | bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA (power house of the cell) |  | 89 |
| 13949558162 | mitosis | part of eukaryotic cell division during which the cell nucleus divides |  | 90 |
| 13949560516 | negative feedback | a mechanism of response in which a stimulus initiates reactions that reduce the stimulus | 91 | |
| 13949564030 | net primary productivity | the rate at which biomass accumulates in an ecosystem | 92 | |
| 13949567616 | nucleus | control center of the cell |  | 93 |
| 13949582087 | osmoconformer | organism that allows its internal concentration of salts to change in order to match the external concentration of salts in the surrounding water | 94 | |
| 13949584214 | osmoregulatory | control of levels of solutes in cells | 95 | |
| 13949587976 | osmosis | diffusion of water across a selectively permeable membrane | 96 | |
| 13949587977 | passive transport | the movement of substances across a cell membrane without the use of energy by the cell | 97 | |
| 13949589884 | periodic disturbances | a temporary change in environmental conditions that causes a pronounced change in an ecosystem | 98 | |
| 13949592089 | pheromones | odorless chemicals that serve as social signals to members of one's species | 99 | |
| 13949594694 | photosynthesis | conversion of light energy from the sun into chemical energy | 100 | |
| 13949594695 | phylogeny | evolutionary history of a species or group of species | 101 | |
| 13949596933 | positive feedback | feedback that tends to magnify a process or increase its output | 102 | |
| 13949602460 | primary succession | succession that occurs on surfaces where no soil exists | 103 | |
| 13949605686 | producer | organism that makes its own food | 104 | |
| 13949607623 | regeneration | replacement of destroyed tissue by the same kind of cells | 105 | |
| 13949607624 | ribosome | site of protein synthesis |  | 106 |
| 13949613048 | rough ER | portion of the endoplasmic reticulum studded with ribosomes |  | 107 |
| 13949618209 | endoplasmic reticulum | system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids |  | 108 |
| 13949620912 | RuBisCo | the most abundant protein on earth -- performs Carbon Fixation in the Calvin Cycle | 109 | |
| 13949626631 | secondary succession | type of succession that occurs in an area that was only partially destroyed by disturbances | 110 | |
| 13949650793 | sexual reproduction | type of reproduction in which cells from two parents unite to form the first cell of a new organism | 111 | |
| 13949652794 | smooth ER | portion of the endoplasmic reticulum that is free of ribosomes |  | 112 |
| 13949655595 | transcription factor | regulatory protein that binds to DNA and affects transcription of specific genes | 113 | |
| 13949656962 | trophic levels | levels of nourishment in a food chain |  | 114 |
| 13949665549 | vegetative reproduction | a form of asexual reproduction in which offspring grow from a part of a parent plant | 115 | |
| 13949802295 | alternative splicing | splicing of introns in a pre-mRNA that occurs in different ways, leading to different mRNAs that code for different proteins -- increases the diversity of proteins | 116 | |
| 13949808869 | aneuploidy | the presence of an abnormal number of chromosomes in a cell | 117 | |
| 13949811049 | cell plate | the precursor of a new plant cell wall that forms during cell division and divides a cell into two | 118 | |
| 13949813512 | centromere | region of a chromosome where the two sister chromatids attach |  | 119 |
| 13949816882 | cleavage furrow | area of the animal cell membrane that pinches in and eventually separates the dividing cell | 120 | |
| 13949822601 | codominance | condition in which neither of two alleles of a gene is dominant or recessive |  | 121 |
| 13949826533 | conjugation | temporary union of two organisms for the purpose of DNA transfer | 122 | |
| 13949829977 | crossing over | the exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring |  | 123 |
| 13949833356 | cytokinesis | division of the cytoplasm | 124 | |
| 13949833357 | DNA | complex molecule containing the genetic information that makes up the chromosomes | 125 | |
| 13949836637 | DNA ligase | an enzyme that eventually joins the sugar-phosphate backbones of the Okazaki fragments | 126 | |
| 13949839214 | DNA methylation | adding a methyl group to DNA | 127 | |
| 13949839215 | DNA polymerase | enzyme that catalyzes the formation of the new DNA strand | 128 | |
| 13949844562 | DNA replication | process in which DNA makes a duplicate copy of itself | 129 | |
| 13949855075 | epistasis | a gene at one locus alters the phenotypic expression of a gene at a second locus | 130 | |
| 13949855077 | genotype | genetic makeup of an organism | 131 | |
| 13949856980 | helicase | enzyme that untwists the double helix of DNA at the replication forks | 132 | |
| 13949860163 | hemizygous | gene present on the X chromosome that is expressed in males in both the recessive and dominant condition | 133 | |
| 13949863215 | heterochromatin | eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed | 134 | |
| 13949865484 | heterozygous | having two different alleles for a trait | 135 | |
| 13949865485 | homologous chromosomes | chromosomes that have the same sequence of genes and the same structure | 136 | |
| 13949870822 | homozygous | having two identical alleles for a trait | 137 | |
| 13949873072 | incomplete dominance | situation in which one allele is not completely dominant over another allele |  | 138 |
| 13949877106 | independent assortment | independent segregation of genes during the formation of gametes | 139 | |
| 13949881375 | inducible operon | operon under positive control, usually "off" but can be turned "on" | 140 | |
| 13949884632 | kinetochore | specialized region on the centromere that links each sister chromatid to the mitotic spindle |  | 141 |
| 13949889475 | lagging strand | discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork | 142 | |
| 13949892446 | leading strand | the new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction | 143 | |
| 13949894691 | linked traits | genes that do NOT assort independently because they are on the same chromosome | 144 | |
| 13949894692 | lysogenic cycle | a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA | 145 | |
| 13949897232 | lytic cycle | a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses | 146 | |
| 13949897233 | mendelian genetics | pattern of inheriting characteristics that follows the laws formulated by Gregor Mendel |  | 147 |
| 13949915451 | nondisjunction | error in meiosis in which homologous chromosomes fail to separate | 148 | |
| 13949915452 | nucleotide | monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base |  | 149 |
| 13949917062 | operon | group of genes operating together | 150 | |
| 13949918906 | pilus | a protein filament that projects from the surface of some prokaryotic cells (hair-like) | 151 | |
| 13949924919 | polygenic inheritance | combined effect of two or more genes on a single character | 152 | |
| 13949924920 | polyploidy | condition in which an organism has extra sets of chromosomes | 153 | |
| 13949928507 | purine | a nitrogenous base that has a double-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; either adenine or guanine | 154 | |
| 13949928525 | pyrimidine | a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; thymine, cytosine, or uracil | 155 | |
| 13949930368 | repressible operon | transcription is usually on, but can be inhibited (repressed) when a specific small molecule binds allosterically to a regulatory protein | 156 | |
| 13949932283 | RNA | single-stranded nucleic acid that contains the sugar ribose | 157 | |
| 13949962146 | sex-linked traits | traits that are inherited with sex chromosomes | 158 | |
| 13949962147 | splicing | removal of introns and connection of exons | 159 | |
| 13949964876 | synapsis | the pairing of homologous chromosomes during meiosis | 160 | |
| 13949967065 | telomere | repetitive DNA at the end of a eukaryotic chromosome | 161 | |
| 13949967066 | transduction | conversion of one form of energy into another | 162 | |
| 13949968979 | transformation | process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria | 163 | |
| 13949974264 | active site | a region on an enzyme that binds to a protein or other substance during a reaction | 164 | |
| 13949977271 | alimentary canal | digestive tube that extends from the mouth to the anus | 165 | |
| 13949991649 | allosteric regulation | binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site | 166 | |
| 13949994034 | alveoli | air sacs in the lungs | 167 | |
| 13949996472 | amino acid | monomer of protein |  | 168 |
| 13950001521 | atom | the basic unit of a chemical element | 169 | |
| 13950001522 | atomic mass | the weighted average of the masses of the isotopes of an element | 170 | |
| 13950006086 | atomic number | number of protons | 171 | |
| 13950006087 | atomic weight | the number of protons plus the number of neutrons | 172 | |
| 13950011940 | atrium | upper chamber of the heart | 173 | |
| 13950011941 | carbohydrate | compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body |  | 174 |
| 13950014539 | cell wall | strong, supporting layer around the cell membrane in plant cells | 175 | |
| 13950018771 | centriole | structure in an animal cell that helps to organize cell division | 176 | |
| 13950018772 | cholesterol | lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids | 177 | |
| 13950025249 | coenzyme | organic cofactor | 178 | |
| 13950025250 | cofactor | nonprotein component | 179 | |
| 13950028476 | covalent bond | a bond formed when atoms share one or more pairs of electrons | 180 | |
| 13950034232 | disaccharide | any of a class of sugars whose molecules contain two monosaccharide residues |  | 181 |
| 13950036646 | electron | negatively charged particle | 182 | |
| 13950041493 | fatty acid | hydrocarbon chain often bonded to glycerol in a lipid | 183 | |
| 13950250005 | flame cell | specialized cell that filters and removes excess water from the body of a flatworm | 184 | |
| 13950257962 | glycolipids | carbohydrates covalently bonded to lipids | 185 | |
| 13950260054 | hormone | the secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect | 186 | |
| 13950260055 | hydrogen bond | weak attraction between a hydrogen atom and another atom | 187 | |
| 13950262563 | hydrophilic | water loving | 188 | |
| 13950264441 | hydrophobic | water hating | 189 | |
| 13950267041 | invasive species | plants and animals that have migrated to places where they are not native | 190 | |
| 13950267042 | ionic bond | the attraction between oppositely charged ions | 191 | |
| 13950268846 | isotope | atoms of the same element that have different numbers of neutrons | 192 | |
| 13950270924 | keystone species | a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically | 193 | |
| 13950273213 | kidney | organ that removes urea, excess water, and other waste products from the blood and passes them to the ureter | 194 | |
| 13950275159 | malphigian tubule | saclike organs that extract waste from blood. | 195 | |
| 13950279108 | nephridia | excretory organs that filter fluid in the coelom | 196 | |
| 13950283263 | neuron | nerve cell | 197 | |
| 13950285561 | neurotransmitter | chemical messengers that cross the synaptic gaps between neurons | 198 | |
| 13950285562 | neutron | no charge | 199 | |
| 13950285563 | niche | an organism's particular role in an ecosystem | 200 | |
| 13950300431 | nonpolar covalent bond | a covalent bond in which the electrons are shared equally by the two atoms | 201 | |
| 13950304640 | nucleolus | produces ribosomes | 202 | |
| 13950311479 | peptide bond | covalent bond formed between amino acids | 203 | |
| 13950311480 | phagocytosis | process in which extensions of cytoplasm surround and engulf large particles and take them into the cell | 204 | |
| 13950313025 | phospholipid | a lipid that contains phosphorus and that is a structural component in cell membranes | 205 | |
| 13950321547 | plasma membrane | selectively-permeable phospholipid bilayer forming the boundary of the cells | 206 | |
| 13950325419 | polar covalent bond | covalent bond in which electrons are not shared equally | 207 | |
| 13950325420 | polysaccharide | large macromolecule formed from monosaccharides | 208 | |
| 13950328133 | proton | positive charge | 209 | |
| 13950330197 | radioactive isotope | isotope whose nucleus decays spontaneously, giving off particles and energy | 210 | |
| 13950333085 | steroid | lipid molecule with four fused carbon rings | 211 | |
| 13950336445 | substrate | reactant of an enzyme-catalyzed reaction | 212 | |
| 13950339433 | triglyceride | a lipid made of three fatty acid molecules and one glycerol molecule | 213 | |
| 13950339434 | valence electrons | electrons in the outermost shell | 214 | |
| 13950341527 | Van der Waals interactions | individually weak and occur only when atoms and molecules are very close together | 215 | |
| 13950361181 | ventricle | lower chamber of the heart | 216 |
