genetics 2 Flashcards
Variations on Mendelian genetics with one gene
Alleles not completely dominant/recessive
Gene with more than two alleles
Gene produces multiple phenotypes
Variations on Mendelian genetics with one gene
Alleles not completely dominant/recessive
Gene with more than two alleles
Gene produces multiple phenotypes
Complete dominance(seed form)- phenotypes of heterozygote and dominant homozygote identical Incomplete dominance- phenotype of heterozygote intermediate the dominant allele is not completely express when the recessive allele is around Codominance- two dominant alleles affect phenotype in separate, distinguishable ways
Complete dominance-
phenotypes of heterozygote and dominant homozygote identical
Incomplete dominance- phenotype of heterozygote intermediate
the dominant allele is not completely express when the recessive allele is around
Codominance- two dominant alleles affect phenotype in separate, distinguishable ways
Codominance: both trait show up \_\_\_\_\_\_ •RR= red cow hairs •RW= red and white cow hairs •WW= white cow hairs •Erminette chickens •BB= black feathers •BW= black and white feathers •WW= white feathers
Codominance: both trait show up Roan cows •RR= red cow hairs •RW= red and white cow hairs •WW= white cow hairs •Erminette chickens •BB= black feathers •BW= black and white feathers •WW= white feathers
polygenic gene: Polygenic inheritance- additive effect of two or more genes on single phenotype many gene affect one trait example: eyecolor height
polygenic gene: Polygenic inheritance- additive effect of two or more genes on single phenotype many gene affect one trait example: eyecolor height
epistasis:
multifactorial traits
gene at one locus alters phenotypic expression of gene at second locus
eg: fur color
Coat color (one gene= pigment, second gene= whether pigment is deposited)
epistasis:
multifactorial traits
gene at one locus alters phenotypic expression of gene at second locus
eg: fur color
Coat color (one gene= pigment, second gene= whether pigment is deposited)
multifactorial trait:
Multifactorial traits- traits depend on multiple genes combined with environmental influences
eg: cancer
multifactorial trait:
Multifactorial traits- traits depend on multiple genes combined with environmental influences
eg: cancer
sex-linked trait:
Sometimes genes are found only on X (usually) or Y chromosome •______ •Orange coat gene in cats •Females compensate with X inactivation (random in non-marsupial mammals)
sex-linked trait:
Sometimes genes are found only on X (usually) or Y chromosome •Hemophilia •Orange coat gene in cats •Females compensate with X inactivation (random in non-marsupial mammals)
common recessive disease:
_______, sickle-cell anemia
carriers have recessive allele but the normal phenotype
common recessive disease:
cystic fibrosis, sickle-cell anemia
carriers have recessive allele but the normal phenotype
dominant disorders:
dominant disorders are rare, arsie by mutation
eg: Huntington’s disease
dominant are not common
dominant disorders:
dominant disorders are rare, arsie by mutation
eg: Huntington’s disease
dominant are not common
Polygenic inheritance is the additive effect of two or more genes on single ____________ (e.g. skin color)
Polygenic inheritance is the additive effect of two or more genes on single phenotype (e.g. skin color)
____________ is when a gene influences multiple phenotypic traits (e.g. _______).
pleiotropy is when a gene influences multiple phenotypic traits (e.g. cystic fibrosis). mucus buildup in organs, abnormal nutrient absorption
Many genetic disorders are rare and caused by recessive alleles. The chance of mating between ____________ increases for relatives (e.g. albinism).
Many genetic disorders are rare and caused by recessive alleles. The chance of mating between relatives increases for disease (e.g. albinism)
Polygenic inheritance is the additive effect of two or more genes on single ____________ (e.g. _____)
Polygenic inheritance is the additive effect of two or more genes on single phenotype (e.g. skin color)
Multifactorial traits depend on _______ combined with _____ influences (e.g. _____)
Multifactorial traits depend on multiple genes combined with environment influences (e.g. cancer).
Many genetic disorders are rare and caused by recessive alleles. The chance of mating between ____________ increases for relatives (e.g.).
Many genetic disorders are rare and caused by recessive alleles. The chance of mating between relatives increases for disease (e.g. albinism)白化病