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34 Cards in this Set
- Front
- Back
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Genetics |
the scientific study of heredity |
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Heredity |
the delivery of characteristics fromparents to offspring |
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Gregor Mendel |
AustrianMonkborn in 1822. Workedin the monastery garden while he was teaching high school. Performedexperiments with pea plants which served as a “model” organism |
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Fertilization |
thecombination of reproductive cells (egg and sperm/pollen) to produce a new cell |
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Homologous Chromosomes |
pairsof chromosomesin which an individual has a corresponding chromosome from eachparent. |
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Diploid Cell |
acell that has two copies of each chromosome Use 2n todesignate Allbody cells except gametes have the diploid number of chromosomes |
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Haploid Cell |
acell that contains half the diploid number of chromosomes •Oneset of chromosomes rather than two •Use n todesignate •Gameteshave the haploid number of chromosomes |
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Meiosis |
theprocess in which the number of chromosomes per cell is cut in half through theseparation of homologous chromosomes in a diploid cell •Chromosomesreplicate one time during interphase •Cell divisionoccurs two times; Meiosis I and Meiosis II •Producesfour cells total |
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ProphaseI |
•Eachhomologous chromosome that has been replicated pairs up with its partner toform a tetrad •Withinthe tetrad, crossing over occurs, which swaps genetic material between homologous •Thiscrossing over recombines genetic information in new ways |
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MetaphaseI |
•Thetetrads of homologous chromosomes line up at the metaphase plate in the middleof the cell |
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AnaphaseI |
•Thehomologous pairs are separated by the work of the spindle fibers •Thereplicated sister chromatids are still held together |
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TelophaseI |
•Theseparated chromosomes segregate at opposite ends of the cell •Nuclearenvelope re-forms •Cytokinesiscleaves the cell into two distinct cells |
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ProphaseII |
•Chromosomescondense/become visible •Notetrads are formed |
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MetaphaseII |
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AnaphaseII |
•The spindlefibers work to pull the sister chromatids apart toward the cells |
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TelophaseII |
•Nuclearenvelope re-forms •Cytokinesiscleaves each into two daughter cells •Fourhaploid cells are produced |
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Life Cycle |
theprocess to go from one adult generation to the next adult generation. |
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Gene Linkage |
alleles of different genes tend to be inherited together from one generation tothe next when they are located on the same chromosome or near each other •Goesagainst the Law of Segregation •Fruitfly eyes color and wing shape •Humanred hair and freckles |
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Gene Mapping |
thedisplay of a genes and their locations within a chromosome •Genesare found at loci (locus) •The furthera gene is from another gene, the greater chance of crossing over between them. |
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truebreeding |
Peastypically self-fertilize |
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CrossPollination of Peas |
•Mendelcross pollinated pea plants that varied in different traits, each with two distinctcharacteristics. •Seed Color:yellow or green •FlowerPosition: axial or terminal •PlantHeight: tall or short •SeedShape: wrinkled or round •SeedCoat: white or grey •PodShape: smooth or constricted •PodColor: green or yellow •FlowerColor: purple or white |
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Hybrids |
offspring of the cross pollinated peas |
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Eachhybrid of the initial crosses displayed the same one characteristic |
•SeedColor: yellow •FlowerPosition: axial •PlantHeight: tall •SeedShape: round •SeedCoat: grey •PodShape: smooth •PodColor: green •FlowerColor: purple |
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genes |
An individual’s characteristics aredetermined by factors that are passed from one parental generation to the next |
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Alleles |
differentforms of a gene (code for different characteristics) |
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Parents |
PGeneration |
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firstfilial generation |
–offspring of P generation. F1 •All F1 hybrid plants expressed only oneparent’s characteristic |
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Principle of Dominance |
statesthat some alleles are dominant and some alleles are recessive •Anorganism with at least one dominant allele for a trait will express that formof the trait •Therecessive form of the trait will only be expressed when the dominant allele isabsent |
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secondfilial generation |
F2. offspring of the F1 X F1 •Recessivealleles reappeared •About¼ of the offspring displayed the recessive trait and the remaining ¾ expressedthe dominant trait. |
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Segregation |
theseparation of the dominant and recessive alleles for a trait. •Separation occurs during the production of thegametes (sex cells) •Gameteswill only carry one form of each gene |
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Genotype |
genetic makeup of an organism •Homozygous –two identical alleles for a gene •Homozygousdominant (TT) •Homozygousrecessive (tt) •Heterozygous –alleles for a gene are differentTt |
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Phenotype |
–physical traits/appearance •Example:Tall orshort |
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Punnett Square |
asimple diagram that uses mathematical probability to help predict the genotypeand phenotype combinations in genetic crosses
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TwoFactor Cross F1 |
•Mendelcrossed true-breedingplants with round, yellow seeds with plants that produced green, wrinkledseeds.Parent1Genotype: RRYY Parent 2 Genotype: rryy •All offspringwere yellow and round •Heneeded toproduce the F2 to see if the genes influenced eachother |
