Polyploidy

• What is polyploidy?

  the condition where an organism has more than 2 complete sets of chromosomes (3n, 4n, 5n...)
• Polyploidy is caused by...

  • failure of cytokinesis to occur
  • failure of spindle fibre formation -> nuclear membrane reforms around unseparated chromatids or unseparated chromosomes
  • (rare) disjunction -> all chromosomes pulled to one pole
• What are polyploid cells?

  gametes and somatic cells containing multiples of haploid number of chromosomes
• Triploidy?

  3 sets of chromosomes
• Tetraploidy?

  4 sets of chromosomes
• Alloploidy?


  occurs when a polyploidy individual has sets of chromosomes derived from different species