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Unformatted text preview: • Downsyndrome is caused by aneuploidy (3 of chromosome 21) • Causes: – Non-disjunction during meiosis – Also occurs in cancer cells during mitosis • Non-disjunction during meiosis Structural Aberrations in Chromosomes • Deletion – a chromosome fragment breaks off and does not rejoin any chromosome • Inversion – a chromosome fragment breaks off and rejoins the same chromosome, but in the inverted orientation • Translocation – non-homologous chromosomes exchange peices • Duplication – unequal crossing over results in a chromosome with a region duplicated Key Points • Autosomal Dominant, Autosomal Recessive, and X-linked disorders have unique patterns of inheritance • Non-disjunction during meiosis can be one cause of Polyploidy or Anuploidy • Aberrations can also occur within a given chromosome...
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- Spring '11
- Genetic disorder, Sex linkage, recessive disorders, single faulty allele