Meiosis is the process by which diploid cells undergo two cell divisions to produce haploid gametes. It starts with a diploid cell that undergoes cell reproduction through mitosis. The two daughter cells then go through meiosis, swapping genetic material and splitting again to produce four haploid daughter cells. Meiosis involves the phases of prophase I, metaphase I, anaphase I, telophase I, and cytokinesis I to separate the homologous chromosomes and produce two haploid cells.

1. Meiosis
Biology Class- Ms. Fields
9th Grade

2. What is Meiosis, Ms.
Fields?
Good Question!
Meiosis is the process of diploid, multi-cellular organisms
reproducing!
• You start with a diploid cell,
• It must go through cell reproduction (mitosis),
• The two daughter cells then go through meiosis!
• They swap genetic material,
• Split again,
• And you are left with four, secondary daughter, haploid, gamete,
reproduction cells!
• Hurray!

3. Prophase I
– Centromeres appear,
– Spindle Fibers begin to form,
– Centromeres migrate to the two poles,
– Nuclear Envelope begins to disappear.

4. Metaphase I
– Spindle fibers “spout” from centrosomes
– Spindle fibers grab a hold of the PAIR of the homologous chromosomes
– Until Metaphase in mitosis, ONE pole grabs ONE pair of chromosomes

5. Anaphase I
– Spindle fibers bring the pair of chromosomes back to the pole.

6. Telophase I
– Chromosomes reach the destination (finally!)
– Spindle fibers begin to break down,
– Nuclear envelope begins to form.

7. Cytokinesis I
– Nuclei redevelop,
– Cytoplasm develops (with the
organelles)
– Divided into daughter cells (4!!!)
– Haploid, daughter cells:
• Pair of sister chromatids:
– Represents ONE chromosomes

8. Work Cited
• http://www.phschool.com/science/biology_place/biocoach/meiosis/proi.html
• http://www.phschool.com/science/biology_place/biocoach/meiosis/metai.html
• http://www.phschool.com/science/biology_place/biocoach/meiosis/anai.html
LINK TO THE HOMEWORK FOR THIS WEEK!
HOW MEIOSIS WORKS:
http://highered.mcgraw-
hill.com/sites/9834092339/student_view0/chapter11/how_meiosis_works.html
STAGES OF MEIOSIS:
http://highered.mcgraw-
hill.com/sites/9834092339/student_view0/chapter11/stages_of_meiosis.html