4. Mitosis and Meiosis

• Mitosis partitions chromosomes into dividing cells
• Prophase:

  • Prophase involves the condensation of chromosomes
  • Prometaphase and Metaphase follow Prophase
• Anaphase:

  • Anaphase involves the separation of chromosomes towards opposite poles
• Telophase:

  • Telophase marks the final stage of mitosis
• Meiosis reduces the chromosome number from diploid to haploid in germ cells and spores
• An Overview of Meiosis precedes the First Meiotic Division: Prophase I
• Prophase I stages:

  • Leptonema (Leptotene stage)
  • Zygonema (Zygotene stage)
  • Pachynema (Pachytene stage)
  • Diplonema (Diplotene stage)
  • Diakinesis
• Importance of crossing-over:

  • Leads to new combinations of alleles
  • Increases genetic variability within a species
• Metaphase, Anaphase, and Telophase I follow the Prophase I stages
• The Second Meiotic Division is part of the process of meiosis
• Spermatogenesis and Oogenesis differ in the development of gametes
• Meiosis is crucial for the successful sexual reproduction of all diploid organisms