1. Mitosis and Meiosis

2. Mitosis is a single cell division with the aim toproduce 2 identical daughter cells It is used for reproduction in prokaryotes andasexually reproducing organisms only In eukaryotes, mitosis is used for growth andrepair Mitosis does not increase variability as thedaughter cells are identical to the parent cell 3. Mitosis is more complicated in eukaryotesbecause more information needs to be copied This is the reason why chromosomes formduring cell division 4. Interphase: DNA replicates and centrosomesduplicate 5. Prophase: Chromatin condenses to formchromosomes with a centromere. The nuclearmembrane disappears. The centrosomes moveaway from each other to either side of the cell. 6. Metaphase: The chromosomes move to theequator of the cell. The mitotic spindle attachesto the centromere on each side of thechromosome. 7. Anaphase: The mitotic spindle pulls one sisterchromatid of each chromosome to one end ofthe cell. 8. Telophase: The chromosomes startdisappearing as the nuclear membrane formsaround the DNA. The cells begin to divide atthe equator. 9. Cytokinesis: A cleavage furrow pinches the cellin two. The nuclear membrane hasreformed, containing the DNA in the form ofchromatin. 10. Only occurs in sexually reproducing organisms The goal of Meiosis is to produce gametes 2 cell divisions result in 4 daughter cells The chromosome number is halved Meiosis increases variability as no 2 gametesare the same 11. Meiosis 1 undergoes the same IPMATC stagesas in Mitosis, but the chromosomes behavedifferent in some stages 12. As the chromatin condenses toform chromosomes, thechromosomes line up in pairs Crossing over occurs betweenadjacent sisterchromatids, with eachhomologous pair having oneor more chiasmata 13. During metaphase, thechromosome pairs lineup together at theequator of the cell 14. The spindles will now attach to the centromereand pull the whole chromosome to one end ofthe cellTelophase 1 15. Meiosis 2 is a simple cell division that goesthroughProphase, Metaphase, Anaphase, Telophaseand Cytokinesis in the same way as in Mitosis The result are 4 gametes, each with half theoriginal number of chromosomes Every gamete is unique due to crossing overand independent assortment of chromosomes