Syllabus Edition

First teaching 2014

Last exams 2024

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Meiosis II (DP IB Biology: HL)

Revision Note

Phil

Author

Phil

Expertise

Biology

Meiosis II

Second division of Meiosis : Meiosis II

  • There is no interphase between meiosis I and meiosis II so the DNA is not replicated
  • The second division of meiosis is almost identical to the stages of mitosis
  • Prophase II
    • The nuclear envelope breaks down and chromosomes condense
    • A spindle forms at a right angle to the old one
  • Metaphase II
    • Chromosomes line up in a single file along the equator of the spindle
  • Anaphase II
    • Centromeres divide and individual chromatids are pulled to opposite poles
    • Sister chromatids separate in meiosis (anaphase) II
      • However, they are likely to be non-identical sister chromatids at this stage due to crossing over having happened in prophase I
    • This creates four groups of chromosomes that have half the number of chromosomes compared to the original parent cell
  • Telophase II
    • Nuclear membranes form around each group of chromosomes
  • Cytokinesis
    • Cytoplasm divides as new cell surface membranes are formed creating four haploid cells

Meiosis II PMA, downloadable AS & A Level Biology revision notes

Prophase II, Metaphase II and Anaphase II in Meiosis II of an animal cell

 

Meiosis II T, downloadable AS & A Level Biology revision notes

Telophase II and cytokinesis in Meiosis II of an animal cell

Exam Tip

Because of the many similarities between mitosis and meiosis II, you are more likely to get a detailed question on meiosis I than meiosis II and the sources of variation that occur in meiosis I. Revise them both though!

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Phil

Author: Phil

Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. He has 15 years of teaching and tutoring experience, teaching Biology in schools before becoming director of a growing tuition agency. He has also examined Biology for one of the leading UK exam boards. Phil has a particular passion for empowering students to overcome their fear of numbers in a scientific context.