ANEUPLOIDY

• WHAT IS ANEUPLOIDY?

  changes in number of individual chromosomes
• WHEN DOES ANEUPLOIDY OCCUR?

  when chromosomes fail to separate in meiosis
• WHAT DOES ANEUPLOIDY LEAD TO?

  a gamete having one more or one fewer chromosome
• WHAT IS AN EXAMPLE OF ANEUPLOIDY?

  down syndrome (3 copies of chromosome 21)
• EXAMPLE OF NON-DISJUNCTION IN MEIOSIS I?

  1. Each homologous pair is doubled due to DNA replication in interphase
  2. Non-disjunction in meiosis I
  3. Means one chromosome does not separate equally
  4. Normal division in meiosis II
  5. Chromatids separate equally
  6. Creating two haploid gametes with one extra chromosome and two haploid gametes missing one chromosome
• EXAMPLE OF NON-DISJUNCTION IN MEIOSIS II?

  1. Each homologous pair is doubled due to DNA replication in interphase
  2. Normal division in meiosis I
  3. Normal division in meiosis II of one cell
  4. Creating two haploid gametes
  5. Non-disjunction in meiosis II of other cell
  6. Creating one haploid gamete missing a chromosome and one haploid gamete with an extra chromosome