Meiosis II Overview

• Meiosis II: Follows meiosis I, completing the meiotic process.
• Interphase II: Possible "rest period" before meiosis II, depends on cell type and species.

Stages of Meiosis II

Prophase II

• Start with two cells: Meiosis II starts with two cells from meiosis I.
• Nuclear envelope dissolves: Similar to prophase in mitosis.
• Chromosome condensation: Chromosomes condense, may have crossover sections from prophase I.
• Centrosome duplication: Centrosomes replicate and migrate to opposite ends.

Metaphase II

• Centrosomes at poles: Centrosomes move to opposite poles.
• Chromosomes align at equator: Similar to metaphase in mitosis.
• Microtubules: Attach to kinetochores and push centrosomes apart.

Anaphase II

• Sister chromatids separate: Unlike meiosis I, similar to anaphase in mitosis.
• Chromatids become daughter chromosomes: Pulled apart into separate cells.
• Microtubule action: Use of motor proteins to move chromatids.

Telophase II

• Formation of four cells: From the original two cells.
• Chromatid unraveling: Chromatids start to unravel into chromatin form.
• Nuclear envelope reformation: Nuclear envelope re-forms around chromatin.
• Cytokinesis: Completes the division, resulting in four haploid cells.

Key Points

• Haploid Cells: Resulting cells have a haploid number (half the initial diploid number).
• Comparison to Mitosis: Meiosis II preserves chromosome number, similar to mitosis.
• Purpose: Produces gametes for sexual reproduction.
• Gametes: Ready to fuse with another gamete (e.g., sperm with egg) to restore diploid chromosome number.