Autosomes vs. Sexchromosomes

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Autosomes vs. Sex-chromosomes
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Sex-linked traits

• Most human traits are inherited by passing
  autosomes non-sex chromosomes
• (just like peas)
• Sex-linked traits inherited by passing
  sex-chromosomes.
• Many human diseases including
• Hemophilia Color blindness

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Autosomal Dominant diseases

• Individuals have the trait if they have the
  dominant allele.
• Ex familial hypercholesterolemia
• Huntingtons disease
• Dwarfism
• Neurofibromatosis
• Colon cancer
• Kidney disease
• Etc.

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Pedigree Analysis

• pedigree,
• derived from the French expression pied de grue
  or Cranes foot, (type of bird) from the
  branching pattern of the diagram. The standard
  symbols used for drawing a human pedigree are
  shown on the right

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• The position of individuals within the pedigree
  is indicated by Roman numerals for the generation
• Ex

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Reading pedigrees (clues)

• Autosomal recessive traits
• skips a generation
• unaffected parents have affected kid
• males and females equally affected
• 2 affected parents always have affected kids.
• Autosomal dominant traits
• no affected children without at least one
  affected parent
• does not skip generations
• seen in about half the offspring of affected
  individuals
• X-linked recessive
• seen more often in males
• skips generations
• trait is passed from maternal grandfather to
  grandson not expressed in mother
• (she is carrier)
• never passed father to son
• X-linked dominant

After selecting your choice, you should prove
your answer to yourself (and me) by doing punnett
squares
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Practice

• What is the mode of inheritance for the 2
  pedigrees below. Prove your answer using punnett
  squares.