Chromosome Mutation

• Chromosome Mutations

  1. Organisms can have additional whole sets of chromosomes
  2. An individual chromosome can fail to separate during anaphase in Meiosis
  3. Changes in Chromosome structure can occur
• Down’s Syndrome

  A common result of Non-Disjunction, a failure in separation in one of the chromosomes can result in a gamete with 24 chromosomes
• Klinefelter’s Syndrome

  • When a Non-disjunction in one of sex chromosomes results in the Genetic Constition, XXY, XXXY, XXXY etc
  • Those with the condition appear male, but have small testes and no sperm in their ejacualate
• Turner’s Syndrome

  • Another result in the mutation of a sex chromosomes, that results in the Genetic Constitution X0 (45 chromosomes)
  • Phenotypically female but sexually immature, normally don’t survive birth
• Chromosomal Mutations

  • Deletion - Portion of Chromosome is lost, effects development of organism
  • Duplication - Portion of Chromosome is replicated, gene sequence is repeated
  • Inversion - Portion of chromosome is deleted, but reattached in an inverted position, sequence of genes is therefore reversed
  • Translocation - Portion is deleted and rejoined elsewhere