multifactorial traits. nomenclature mendelian trait- trait caused by alleles on ______________...
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Multifactorial TraitsMultifactorial Traits
NomenclatureNomenclature
Mendelian trait- trait caused by alleles on Mendelian trait- trait caused by alleles on ____________________________
____________ trait- trait caused by more ____________ trait- trait caused by more than one gene often on different than one gene often on different chromosomeschromosomes
Multifactorial (complex) trait- trait that has Multifactorial (complex) trait- trait that has _______________________ components_______________________ components
Genetics vs EnvironmentGenetics vs Environment
Polygenic PhenotypesPolygenic Phenotypes
Continuously Continuously varyingvarying
Called a Called a quantitative traitquantitative trait
Genes are called Genes are called quantitative trait quantitative trait ________
_________ is a bell _________ is a bell curvecurve
Locus ModelsLocus Models
Model is based on how many loci Model is based on how many loci code for each polygenic traitcode for each polygenic trait
As the number of genes increase, so As the number of genes increase, so does the amount of phenotypes does the amount of phenotypes possiblepossible
Number of _______________ Number of _______________ determines phenotypedetermines phenotype
Fingerprint PatternsFingerprint Patterns
Dermal ridges form Dermal ridges form patterns of loops, patterns of loops, whorls, or archeswhorls, or arches
Mostly determined by Mostly determined by ______________________
Influenced by touching Influenced by touching fingers and toes to fingers and toes to amniotic sac during amniotic sac during early developmentearly development
Total ridge count Total ridge count (TRC)- count of ridges (TRC)- count of ridges on all fingerprints; on all fingerprints; creates bell curve creates bell curve
HeightHeight
Genetics contribute ________ attainable Genetics contribute ________ attainable heightheight
Environment determines height actually Environment determines height actually attainedattained
Eye ColorEye Color Probably ______, but not multifactorialProbably ______, but not multifactorial True blue eyes- no active True blue eyes- no active
pigment; blue color comes from pigment; blue color comes from scattering of lightscattering of light
Lipochromes- greenish-blue pigmentLipochromes- greenish-blue pigment Melanins- brownish pigmentMelanins- brownish pigment Melanins tend to mask other pigmentsMelanins tend to mask other pigments Other features (flecks, specks, rings, Other features (flecks, specks, rings,
and streaks) come from distribution of and streaks) come from distribution of pigment on the irispigment on the iris
Skin ColorSkin Color
Color created by bits Color created by bits of melanin secreted of melanin secreted by melanocytes by melanocytes within the layers of within the layers of the skinthe skin
Variety created by Variety created by genes coding for genes coding for amount and amount and distribution of distribution of melaninmelanin
Cardiovascular SystemCardiovascular System
GeneticsGenetics Amount of Amount of
cholesterolcholesterol Blood pressureBlood pressure Clotting factorsClotting factors
EnvironmentEnvironment DietDiet ExerciseExercise
WeightWeight
Very complex geneticallyVery complex genetically Feeling of hungerFeeling of hunger MetabolismMetabolism
EnvironmentEnvironment Diet Diet ExerciseExercise
Empiric RiskEmpiric Risk
Rate at which a certain trait occurs Rate at which a certain trait occurs within a _______________within a _______________
Population may be defined vaguely Population may be defined vaguely or very specificallyor very specifically
Risk may increase within certain Risk may increase within certain ethnic groups or if family members ethnic groups or if family members are affectedare affected
HeritabilityHeritability
Expresses proportion of phenotype Expresses proportion of phenotype that is contributed to __________ for a that is contributed to __________ for a particular traitparticular trait
1.0 would be solely based on genetics1.0 would be solely based on genetics Lower number have ________________ Lower number have ________________
componentscomponents Number can change when Number can change when
environment changesenvironment changes
Coefficient of RelatednessCoefficient of Relatedness
_____________ (P)- individual based _____________ (P)- individual based relatedness is based uponrelatedness is based upon
11°- Immediate family members (mother, °- Immediate family members (mother, father, sister, brother, children); share _____ father, sister, brother, children); share _____ of genesof genes
22°- Grandparents, aunts, uncle, nieces, and °- Grandparents, aunts, uncle, nieces, and nephews, grandchildren; share _____ of nephews, grandchildren; share _____ of genesgenes
33°- Great grandparents, great aunts, great °- Great grandparents, great aunts, great uncles, great nieces, great nephews, first uncles, great nieces, great nephews, first cousins, great grandchildren; share ______ of cousins, great grandchildren; share ______ of genesgenes
How do we study nature vs How do we study nature vs nurture?nurture?
Adoption StudiesAdoption Studies Adoptee is compared to adopted parents Adoptee is compared to adopted parents
(environment)(environment) Adoptee is compared to biological parents Adoptee is compared to biological parents
(genetics)(genetics) Twin StudiesTwin Studies
Prevalence of trait between MZ twins is Prevalence of trait between MZ twins is compared to DZ twins (concordance)compared to DZ twins (concordance)
Higher differences in concordance show higher Higher differences in concordance show higher differences in heritability differences in heritability
Association StudiesAssociation Studies
Researchers compare SNP’s (single Researchers compare SNP’s (single nuclear polymorphisms) between nuclear polymorphisms) between individual with and without disordersindividual with and without disorders
Groups with disorder may show a Groups with disorder may show a characteristic set of SNP’scharacteristic set of SNP’s
Can be used to find genes that are causing Can be used to find genes that are causing disorderdisorder
Can be difficult because of genetic Can be difficult because of genetic heterogeneity heterogeneity