Karyotyping and Pedigrees

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Karyotyping and Pedigrees

• Day 1 of Murder Mystery!

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Karyotypes

• A display of the 46 chromosomes
• Tool that geneticists use to study genetic
  disorders

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Pedigrees

• Pedigree is a tool used by geneticists
• Pedigree
• A family tree that records and traces the
  occurrence of a trait in a family
• Men are squares women are circles
• Colored shapes represent individuals that show
  the trait
• Parents connected by horizontal lines w/children
  beneath them
• Whats missing?
• How do we figure out the genotypes of each
  individual?

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Pedigrees Finding the Genotype

• First-born daughter in 3rd generation has
  attached lobes, but both of her parents have
  free.
• We know that attached lobe trait must be
  recessive
• If it were dominant, at least one of the parents
  would have attached lobes
• Both parents are carriers
• Carrier
• Has one copy of allele, but doesnt express it
  (phenotype)
• Ill draw mine

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Pedigrees Sex-linked Disorders