Human genetic inheritance patterns

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  • 1.Human Genetics

2. I. 5 Human Patterns of Inheritance:a. Complete Dominance (Basic Mendelian Genetics)b. Incomplete Dominancec. Co-dominanced. Sex-Linkede. Polygenic 3. a. Complete Dominance Traits inherited are either DOMINANT orRECESSIVE Ex. BB, Bb, bb 4. b. Incomplete Dominance Traits inherited show a new phenotypethat is a BLENDING or MIXING ofparental alleles HETEROZYGOUS results in a blendingof two alleles Use 2 different CAPITAL letters torepresent (neither allele is dominant orrecessive) 5. Incomplete Dominance cont.Ex: 4 oclock flowers, snapdragons, Tay Sachs Disease 6. Incomplete Dominance cont.Ex: 4 oclock flowers, snapdragons, Tay Sachs Disease 7. Incomplete Dominancecont.Ex: 4 oclockflowers, snapdragons, TaySachs Disease 8. c. Co-dominance Trait inherited shows a new phenotype thatEXPRESSES BOTH parental allelesHETEROZYGOUS condition results in theexpression of both alleles Use 2 different capital letters to represent 9. Co-dominance continuedEx: Roan Horse X 10. Co-dominance continuedEx: Roan Horse, Dalmatian 11. d. Sex Linked Traits Traits are controlled by genes onthe X or Y chromosomesa. _X linked traits can be passed on to males and femalesb. _Y linked traits can only be passed to males 12. X-Linked Traits1. Affect the X chromosome2. _FEMALES tend to be CARRIERS and XtYpass on the trait to their sons -3. Females can be affected but BOTH Xchromosomes must have the gene for thetrait - XtXt 13. Examples: 14. Hypertrichosis Human Werewolf Syndrome: Congenital generalized hypertrichosis (CGH) Rare, X-linked dominant traitFound in a single multigenerational Mexican family 15. ColorblindnessSelf Test:NUMBERS: 5 | 8 | 9 | 5 | 3 | 5 | 9 | 10 | 16. Hemophilia 17. Male Pattern Baldness 18. Genotypes of Male Pattern Baldness 19. e. Polygenic Traits Traits are controlled byMULTIPLE gene pairs1.Genes may be on same ordifferent chromosomes2.Expressed trait variesgreatlyEx. Hair color, eye and skincolors, height, weight 20. II. How to study patterns of inheritance infamilies Two Methods: 1. _KARYOTYPE: Photograph of an individualschromosomes arranged in homologous pairs andcan be viewed underneath a microscope a. Used to identify problems with chromosomes _ABNORMAL NUMBERS _DAMAGED OR BROKEN _TO DETECT GENETIC DISEASES 21. Typical Karyotype: Normal Individual Pattern of Inheritance: Normal Chromosome Pattern Abnormality: None Notation: 46, XY, Male 22. 2. _PEDIGREE CHART: Diagram to show genetic traits and used to map genetic traits through generationsa. Shows SEX, PHENOTYPE S, and GENOTYPES of family membersb. Can predict patterns of inheritancec. Uses symbols


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