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AP Biology Genetic Vocabulary Flashcards

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5833135787crossing overProcess in which homologous chromosomes exchange portions of their chromatids during meiosis.0
5833140911law of independent assortmentOne of Mendel's principles that states that genes for different traits can segregate independently during the formation of gametes1
5833144576law of segregation(genetics) the separation of paired alleles during meiosis so that members of each pair of alleles appear in different gametes2
5833148036random fertilizationsource of genetic variation caused by the unlimited number of possible sperm & egg combinations3
5833150864heterozygousAn organism that has two different alleles for a trait4
5833152936monohybrid crossA cross between individuals that involves one pair of contrasting traits5
5833155751dihybrid crossA cross between two individuals, concentrating on two definable traits6
5833158780alleleAn alternative form of a gene.7
5833161345geneA discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). Codes for RNA, polypeptides, and proteins8
5833164474synapsisPairing of homologous chromosomes. homologous chromosomes loosely pair up -align gene by gene -get together with homologous pair9
5833167716dominant alleleAn allele that will determine phenotype if just one is present in the genotype10
5833172225recessive alleleAn allele that is masked when a dominant allele is present11
5833174267phenotypeAn organism's physical appearance, or visible traits.12
5833176681genotypeAn organism's genetic makeup (alleles for a particular gene)13
5833179025test crossthe crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype14
5833181440rule of multiplicationA statistical rule stating that the probability of two independent events occurring together is the product of their individual probabilities.15
5833184577rule of additionA statistical rule stating that the probability of either of two independent (and mutually exclusive) events occurring is the sum of their individual probabilities minus the probability of them both occurring together.16
5833188515complete dominanceA relationship in which one allele is completely dominant over another17
5833191314incomplete dominanceA type of inheritance in which two contrasting alleles contribute to the individual a trait not exactly like either parent; blending inheritance.18
5833193364codominanceBoth alleles are equally expressed19
5833196678multiple allelesthree or more forms of a gene that code for a single trait (but each individual only has 2)20
5833198671pedigreeA diagram that shows the occurrence of a genetic trait in several generations of a family21
5833201364cystic fibrosisan autosomal recessive disorder creating thick sticky mucus which is hard to expel22
5833205416Tay-SachsA human genetic disease caused by a recessive allele for a dysfunctional enzyme, leading to accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth.23
5833207702Sickle cellA human genetic disease of red blood cells caused by the substitution of a single amino acid in the hemoglobin protein; creating sickle shaped red blood cells that collect in vessels causing pain and reduced gas exchange24
5833212635lethal dominant allelehaving a single dominant allele results in death25
5833216115Huntington's diseaseprogressive hereditary disorder characterized by uncontrolled movements- changes in cortex & cerebellum26
5833219350sex-linked genesa gene that is carried on the X or Y chromosome27
5833221694X chromosomeThe sex chromosome found in both men and women. Females have two X chromosomes; males have one. An X chromosome from each parent produces a female child.28
5833223368Y chromosomeThe sex chromosome found only in males. When paired with an X chromosome from the mother, it produces a male child29
5833228010Duchenne Muscular DystrophyA human genetic disease caused by a sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue.30
5833232992HemophiliaA sex-linked hereditary disease where blood does not coagulate to stop bleeding31
5833235389X-inactivationa process by which one of the two copies of the X chromosome present in female mammals is randomly inactivated creating a Barr body32
5833238751Barr BodyThe inactivated X chromosome33
5833241458Genetic recombinationthe regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents34
5833243534linkage mapA genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes.35
5833245521map unitin chromosome mapping, an increment of 1 percent in the frequency of crossing-over36
5833247842nondisjuctionError in meiosis in which homologous chromosomes fail to separate.37
5833250753aneuploidyA chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number.38
5833255062polyploidyCondition in which an organism has extra full sets of chromosomes39
5833257359trisomy3 copies of a chromosome40
5833259355monsomyChromosomal abnormality consisting of the absence of one chromosome from the normal diploid number41
5833261545mutationan event that changes the nucleotide sequence in a gene, creating a novel sequence which may have no function or a new function42
5833263775point mutationGene mutation involving changes in one or a few nucleotides43
5833269835deletion(1) A deficiency in a chromosome resulting from the loss of a fragment through breakage. (2) A mutational loss of one or more nucleotide pairs from a gene.44
5833273487duplicationAn aberration in chromosome structure due to fusion with a fragment from a homologous chromosome, such that a portion of a chromosome is duplicated.45
5833277634inversion(genetics) a kind of mutation in which the order of the genes in a section of a chromosome is reversed46
5833279508translocationChange to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome47
5833282099frameshiftMutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide48
5833283925Down SyndromeA condition of retardation and associated physical disorders caused by an extra copy of chromosome 21.49
5833286026KlinefelterSyndromeA chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY.50
5833291314Turner syndromea monosomic condition where a female has only 1 sex chromosome- the only known viable monosomy in humans51
5833294153true breedingIf an organism has a certain characteristic that is always passed on to its offspring, we say that this organism bred true with respect to that characteristic.52
5833296247linked genesGenes located close enough together on a chromosome that they tend to be inherited together.53
5833298594carrierA person whose genotype includes a gene that is not expressed in the phenotype.54
5833307657G1First stage of interphase in which cell grows and performs its normal functions. Cell is diploid.55
5833309403G0Cell is performing its normal functions, but has left the cell cycle and is not dividing. Does not pass the G1 checkpoint56
5833311459S phaseThe synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.57
5833313280G2Last stage of interphase in which cell grows and performs its normal functions. Cell is diploid.58
5833315003InterphaseCell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases59
5833316544ProphasePhase of mitosis in which chromosomes condense, nuclear membrane disappears, nucleolus disappears, and spindle fibers begin to form.60
5833318234MetaphasePhase of mitosis in which spindle fibers help chromosomes line up on the midline of the cell.61
5833320565AnaphasePhase of mitosis in which the chromosomes separate and move to opposite ends of the cell.62
5833322681TelophasePhase of mitosis during which chromosomes uncoil, a nuclear envelope returns around the chromatin, and a nucleolus becomes visible in each daughter cell"63
5833325607cytokinesisAt the end of telophase, actin fibers form an equator around the cell and contract, separating the cytoplasm into two daughter cells.64
5833328772centrioleA paired cluster of microtubules near the nucleus in animal cells. This organelle organizes spindle fibers during mitosis.65
5833331298centromereRegion of a chromosome where the two sister chromatids attach to one another. Contains the kinetochore.66
5833333340kinetochoreA specialized region on the centromere that links each sister chromatid to the mitotic spindle.67
5833336314spindle fibersMade of microtubules that connect centrioles to kinetochores of chromosomes and that separate sister (mitosis) or homologous (meiosis) chromosomes during cell division68
5833340151chromosomeA threadlike, gene-carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins.69
5833342028chromatidOne of two identical "sister" parts of a duplicated chromosome.70
5833343806haploidA cell with only one copy of each chromosome.gamete -contains a single set of chromosomes -n71
5833346049diploidA cell with two copies of each chromosome.has two sets of chromosomes -human # is 46 -2n72
5833350697karyotypeMicrograph of the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size73
5833352710cancerDisorder in which some of the body's cells lose the ability to control growth; A disease in which the body cells grow & divide uncontrollably, damaging the parts of the body around them.74
5833354133metastisisspread of cancer cells75
5833361765genomeconsists of all the DNA in a cell -holds specific genetic traits76
5833365944somatic cellshave two sets of chromosomes -go through mitosis -nonreproductive body cells77
5833368335gameteshave half as many chromosomes as somatic cells -go through meiosis -reproductive cells78
5833374435metaphase platemidway point between the spindles two poles -where chromosomes line up in metaphase79
5833376185cleavage furrowformed in eukaryotic cells during late telophase and cytokinesis80
5833379626cell plateforms in plant cells during cytokinesis81
5833380978binary fissionprokaryotic method of reproduction and cell division -chromosome replicates and the two daughter chromosomes actively more apart82
5833383409cell cycle control systemdirects sequential event of the cell cycle -regulated by internal and external force -receives signals from the cytoplasm83
5833388864checkpointswhere the cell cycle stops until a go ahead signal is received -G1 is the most important for many cells84
5833392811growth factorsproteins released by certain cells that stimulate other cells to divide85
5833394386density dependent inhibitioncrowded cells stop dividing86
5833399545tumorsmasses of abnormal cells within otherwise normal tissue -formed by cancer cells87
5833401123benign tumor-lump of abnormal cells remaining only at the original site of the cancer88
5833402514malignant tumorinvade surrounding tissue89
5833404222metastasizeexporting cancer cells to other parts of the body, where they may form secondary tumors90
583341950946What is the chromosome number for humans?91
5833422069homologous chromosomes2 chromosomes in each pair -same length and shape -carry genes controlling the same inherited characters92
5833431668fertilizationthe union of gametes (sperm and egg)93
5833433346zygotefertilized egg -one set of chromosomes from each parent -diploid cell produces somatic cells by mitosis94
5833435697prophase 1occupies more than 90% of the time required for meiosis -chromosomes condense -synapse and crossing over -tetrads and chiasmata95
5839571334homozygousAn organism that has identical alleles for a trait96
5839584189Geneticsstudy of how characteristics are passed from parent to offspring97
5839589539Gregor MendelThe "father of genetics"98
5839593519hereditythe passing of characteristics from parents to offspring99
5839601698traita genetically determined characteristic100
5839606729molecular geneticstype of genetics that studies the genes & chromosomes of an organism101
5839632959hybridanother name for a heterozygous genotype102
5839638012probabiltythe chance of some event happening103
5839641848generationa span of time between the birth of parents & the birth of their offspring104
5839656681P (parent) generationthe generation of true-breeding plants105
5839667755F1 generationoffspring of a cross between the P generation106
5839673594F2 generationoffspring of a cross between the F1 generation107
5839683744cellbasic unit of life108
5839685976cell cyclean ordered sequence of events that includes when a eukaryotic cell is first formed to until it divides into two cells109
5839706461mitosisthe process by which the nucleus of a cell divides into two nuclei110
5839715969meiosisthe production of gamete cells111
5839719171sister chromatidthe two chromosomes that make up a matched pair in a diploid cell112
5839731610tetrada paired set of homologous chromosomes, each composed of two sister chromatids113
5839739331punnett squarea tool used to solve probability problems114
5839764139sex chromosomea chromosome that determines whether on individual is a male or female115
5839772254autosomea chromosome not directly involved in determining the sex of an organism116
5839795101sex influenced traita trait expressed in one sex but not the other117
5839811500chromatinthe material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.118
5839817188asexualnot involving the fusion of gametes.119
5839817189sexualthe fusion of gametes120
5839828987chiasmataa point at which paired chromosomes remain in contact during the first metaphase of meiosis, and at which crossing over and exchange of genetic material occur between the strands.121
5839833877centrosomean organelle near the nucleus of a cell that contains the centrioles (in animal cells) and from which the spindle fibers develop in cell division.122
5840909781cyclinsproteins that control the progression of cells through the cell cycle by activating cyclin-dependent kinase (Cdk) enzymes.123
5841039284syngamythe fusion of two cells, or of their nuclei, in reproduction.124
5841046037variationa change or difference in condition, amount, or level, typically with certain limits.125
5841053902synaptonemal complexa ladderlike series of parallel threads; adjacent to and coaxial with pairing chromosomes in meiosis.126
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