1. Meiosis
SC Standard B4.5- The student will be able to summarize the characteristics of the phases of Meiosis I and II

2. Meiosis Much like Mitosis, but two rounds.
Sexual reproduction versus autosomal cell division
End results= 4 haploid daughter cells versus 2 genetically identical daughter cells (diploid)

3. Meiosis I and Meiosis II:
Meiosis I: Chromosome pairs replicate resulting in 2 haploid daughter cells with duplicated chromosomes different from original diploid cell
Meiosis II: haploid daughter cells from Meiosis I divide resulting in 4 haploid daughter cells called gametes with undoubled chromosomes

4. Meiosis I:
Interphase- cells grows, synthesize proteins and first round of DNA replication = duplicate chromosomes, cell prepares for division
Prophase I- Nuclear membrane breaks down, spindle fibers appear, centrioles move to opposite poles. Each chromosome pairs with it’s corresponding homologous chromosome to form a tetrad
Two sister chromatids are attached at centromere. Crossing over occurs here if it occurs

5. Meiosis I Continued
Metaphase I- spindle fibers attach at the centromere and are pulled into the middle of the cell
Anaphase I- spindle fibers pull homologous chromosomes towards opposite poles.
Telophase I and Cytokinesis- nuclear membrane forms, cytoplasm divides, cells separate into 2 haploid daughter cells- each with half the number of chromosomes

6. Meiosis I
prophase I metaphase I anaphase I telophase I

7. Meiosis II
Prophase II- spindle fibers form, nuclear membrane breaks down
Metaphase II- spindle fibers attach and chromosomes line up across the center of the cell
Anaphase II- sister chromatids separate and move to opposite poles
Telophase II and cytokinesis- nuclear membrane reforms, results in 4 haploid daughter cells (N)

8. Meiosis II

9. Comparing: Mitosis Meiosis: 2diploid daughter 4 haploid daughter
cells (2N) cells (N)
Body cells reproductive cells
Production reduction process
process
Both have similar phases they go through