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Meiosis

Meiosis. What is Meiosis???. the process of nuclear division in sexual reproduction where the number of the chromosomes is halved. produces four daughter cells all daughter cells are haploid (half the set)

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Meiosis

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  1. Meiosis

  2. What is Meiosis??? • the process of nuclear division in sexual reproduction where the number of the chromosomes is halved. • produces four daughter cells • all daughter cells are haploid (half the set) • chromosomes are shuffled in the process, so that each daughter cell has a unique combination • used to create gametes (sperm and egg)

  3. Mitosis vs. Meiosis # of Divisions 1 2 Type of Reproduction Asexual Sexual Cells Produced Body Cells Sex cells 2 identical Diploid (2n) cells Total # of Cells at the End 4 not identical Haploid (n) cells

  4. Mitosis vs. Meiosis Total # of Chromosomes in the End 46 23 Crossing Over No Yes Number of Steps 4- PMAT 8- PMAT I PMAT II

  5. A COMPARISON OFSEXUAL VERSUS ASEXUALREPRODUCTION • Sexual Asexual

  6. Sexual Reproduction • Involves the fusion of gametes (Egg and Sperm) • COMBINES GENES FROM TWO DIFFERENT PARENTS TO FORGENETICALLY DIVERSE OFFSPRING.

  7. 8-Phases of Meiosis 1.Prophase- Each Chromosome pairs up 2. Metaphase- Line up in the middle 3. Anaphase- Chromosomes pull apart. 4. Telephase- Cell separates in 2 cells

  8. 8 Phases of Meiosis 5. Prophase II- Chromosomes pair again in the 2 haploid cells. 6. Metaphase II- Line up in the middle 7. Anaphase II- Chromosomes pull apart 8. Telephase/Cytokinesis- Result in 4 haploid (N) daughter cells.

  9. Unique in Meiosis • Crossing Over- homologous chromosomes exchange portions of their chromatids resulting in the exchange of alleles, producing NEW COMBINATIONS!!

  10. Unique in Meiosis • The following images show three separate possibility for a single cell that has undergone meiosis. Look at all the different combinations • Independent Assortment- In addition to Crossing-Over, the process of meiosis ensures that chromosomes are randomly assorted.

  11. Fun Fact • THE 23RD PAIR, THE SEX CHROMOSOMESDETERMINES WHETHER THE PERSON IS FEMALE (XX) OR MALE (XY)

  12. http://www.biologycorner.com/bio1/meiosis.html • http://teachers.dadeschools.net • http://www.web-books.com/MoBio/Free/images/Ch8B1.gif • http://www.colouroptional.com/pictures/samples/personal/pregnant%20pics1.jpg

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