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17 Cards in this Set
- Front
- Back
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SRY gene
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Testes specific transcription factor (role in sex.dev't for males)
If gene is missing or nonfunctional, female devt occurs. |
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transcriptional factor
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protein that turns on other genes
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sex linked traits
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Found on sex chromosomes
Most are Xlinked Males=XY (hemizygous) |
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X linked recessive
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Always expressed in male
In female when homozygous Mothers-sons and daughters Fathers-daughters |
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X linked Dominant
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Rare, more sever in males
Females only need 1 copy to express phyenotype |
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X-Inactivation
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In females only
1 X chromosome condenses (called Barr body)and becomes inactive Occurs early in development XIST gene codes from RNA that binds to X chromosome and inactivates it |
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"Mosaics"
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Females; some cells express genes on maternal X chromosome, some express genes on paternal X chromosome
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Sex-limited Traits
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Affects a structure or function of the body that is present in only males and females
(ex. ovary dev't vs. sperm dev't) |
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Sex-Influenced Traits
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An allele is dominant in 1 sex and recessive in the other
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Genomic Imprinting
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Difference in expression of a gene depending upon whether it was inherited from mother or father.
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types of traits
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Mendelian= due to single gene (but can be multifactorial)
Multifactorial=influenced by enviornment Polygenic= more than 1 gene (can be multifactorial) |
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Empiric Risk
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predictions of recurrence based on trait's incidence in specific population
Based on observations/ epidemiological studies |
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Heritability
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% of phenotypic variation due to genes
H=1..genes only H=0..enviornment only Proportion of ppl sharing a trait compared to proportion predicted to share trait |
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Adoption studies
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share enviornment but not genes with adoptive family
share genes but not enviornment with biological parents |
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Twin Studies
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Concordance= % of pairs in which both twins express the trait
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Single Nucleotide Polymorphism
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Nucleotide site w/ more than 1 allele is a polymorphism.
Site is polymorphic if allele is present in more then 1% of population |
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Association Studies
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Compare group of interest to control group for presence of SNP.
If SNP is present more often in cases then in controls, it is associated w/ trait--> SNP may be near gene impacting trait |
