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| Question | Answer |
| Gregor Mendel | Provided foundation for modern genetics |
| Gregor Mendel details | Austrian Monk Mid 1800's Edible pea plants |
| Gregor Mendel first geneticist to | choose right organism/design performed experiments/analyzed data correctly |
| Self-fertilization | fertilized by sperm from same organism fusion of gametes from w/ in |
| Example Self-fertilization | Pea Plants |
| Cross-fertilization | sperm from different organism fusion of gametes from 2 indv |
| Cross-fertilization example | mating two plants by hand breeders remove stamen dust sticky end of carpel |
| Stamen | male produces pollen |
| Carpel | female produces eggs |
| Parental generation (P) | 2 individual plants being crossed |
| First-generation (F1) | offspring of the parental generation |
| Second-generation (F2) | Offspring of the F1 generation |
| Homozygous (particular characteristic) Pea Plants | always produce the same physical forms purple flowers=purple flowers True-breeding |
| True-breeding | Plants homozygous for a characteristic |
| Dominant | determines the phenotype of heterozygotes completely masks recessive ie: AA or Aa |
| Recessive | expressed fully ONLY in homozygotes ie: aa |
| Law of segregation | 2 alleles of a gene separate from one another at meiosis |
| Genotype | the actual combination of alleles carried by an organism |
| Phenotype | observable/measurable feature of the organism Traits: physical appearance, behavior, blood type |
| Punnett square method named after | R.C. Punnett 1900 geneticist |
| Punnett square method You must be able to determine: | Homozygous vs. heterozygous Dominant vs. recessive allele Gametes Genotypes/Phenotypes genotypic ratio/phenotypic ratio |
| Mendel Hypothesized | Genes on different chromosomes are inherited independently Law of independent assortmen |
| Law of independent Assortment | 2 or more genes are inherited independently of each other Alleles of one gene may be distributed to gametes independently of alleles for other genes |
| alleles of one gene may be distributed to gametes independently of alleles for other genes | metaphase 1 paired homologous chromosomes line up randomly then separate independently during anaphase 1 |
| Genes on the same chromosome | tend to be inherited together Linked |
| Recombination | can create new combinations of linked allels |
| Sex determined sex chromosomes | XX female XY male |
| Sex-linked genes found | Only on X or Y chromosome |
| Y chromosome carries | 78 genes |
| X chromosome carries | 1000 genes only a few have a role in reproduction |
| X genes have no counterpart on Y | to make up for this One X of female is condensed |
| X chromosome genes | color vision blood clotting some structural proteins in muscles |
| Females of 2 X chromosomes | can be homoxygous or heterozygous Dominate vs recessive |
| males only one X Chromosome | full express all alleles on their X (color blindness, hemophilia, muscular dystrophy occur) |
| Y chromosomes contain | SRY gene |
| Mendelian Rules of Inheritance does not apply to all traits because | traits are influenced by: Incomplete dominance co-dominance polygenic inheritance Pleiotropy Environment |
| Incomplete Dominance | Phenotype of heterozygotes is intermediate between the phenotypes of the homozygotes Red + White = Pink Straight hair + Curly hair = Wavy hair |
| Co-Dominance | Single gene may have multiple alleles ie: blood type |
| Polygenic Inheritance | Interaction between 2 or more genes contributes to a single phenotype ie: height, weight, eye color, skin color, wheat color |
| Pleiotropy | A single gene has several phenotypic effects |
| Pleiotropy example | SRY gene (sex-determining Region of the Y chromosome) found 1990 |
| SRY gene | Codes for a protein that activates other genes, which then code for other proteins that switch on male development in an embryo |
| Environment | External surroundings influence gene expression |
| Environment examples | Intelligence (environmental and genetic) Temperature (fur) UV exposure (eye color in babies) |
| Temperature (fur) | enzymes that produce pigments become inactive at certain temperatures heat 93 degrees cold 32 degrees |
| Siamese cats genotype | dark fur all over body enzyme that produces dark pigment inactive above 93F 34F |
| Siamese babies | born white after birth: ears/nose/paws/tail cool and darken |
| Investigating human genetic disorders | Family pedigrees: diagrams that show genetic relationships among a set of related individuals |
| Human genetic disorders are caused by recessive alleles | albinism: defect in melanin production sickle cell anemia: (low blood oxygen) defective allele for hemoglobin synthesis |
| Genetic Disorders Caused by dominate allels | Cleft chin marfan syndrome huntingtons disease |
| Genetic disorders Sex linked | Color blindness hemophilia muscular dystrophy |
| Chromosome number affect humans | 1) Abnormal number of sex chromosomes 2)Abnormal number of autosomes |
| Abnormal number of sex chromosomes | Non-disjunction of sex chromosomes during meiosis ie: Turner syndrome Trisomy X Klinefelter Syndrome Jacob Syndrome |
| Turner Syndrome | females only one X (XO) no menstration no mature eggs cannout bear children 1/3000 |
| Trisomy X | females XXX 1/1000 |
| Klinefelter Syndrome | Males XXY low sperm show mixed secondary sex characteristics 1/1000 |
| Jacob Syndrome | Males XYY high levels of testosterone severe acne tall (over 6 ft) 1/1000 |
| Abnormal number of autosomes 22 pairs | most embryos with 3 copies of autosome spontaneously abort -exeption tristomy 21 -trisomy 18 Trisomy 13 |
| Trisomy 21 | Down syndrome 1/900 90% due to egg 10% due to sperm |
| Trisomy 18 | edward syndrome 50% survive 2 weeks |
| Trisomy 13 | Patau Syndrome 90% die in the first month |
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