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Drill #2 2/24/10. From last night’s reading you learned that traits in families can be tracked through the generations. Please describe why you think this is an important practice. Pedigrees?. Or. A Little Bit of Vocab…. Pedigree :
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Drill #22/24/10 • From last night’s reading you learned that traits in families can be tracked through the generations. Please describe why you think this is an important practice.
Pedigrees? Or
A Little Bit of Vocab…. • Pedigree: A tool used to determine how one particular trait is inherited • Wild-Type: Phenotype that appears most often in the population
Trait Inheritance • Traits can be inherited on either Autosomes or Sex Chromosomes Which Sex Chromosome do you think has more genetic disorders found on it?
Autosomal Inheritance • Autosomal Recessive: • Caused by presence of two recessive alleles (dd) • There are “Carriers” – (Dd) • Do not have the trait, but contain a copy of the allele • Usually does not show up in all generations (skips) Cystic Fibrosis Albinism
Autosomal Inheritance • Autosomal Dominant: • Any copy of a dominant allele will result in the disorder (DD or Dd) • There are no carriers – Why? • A person with Dd has the disorder! Achondroplasia Webbed-Toes Polydactyly
Why are most lethal Dominant alleles uncommon? Usually, autosomal traits show up in 50% males/50% females, why?
Sex Linked • X-Linked Recessive: • Must have only recessive copies of the allele • Female = XdXd – Must have both copies • Male = XdY– Only needs one copy Fruit Flies – White Eyes Color-Blindness Hemophilia
Female “Carriers” Males have trait