1 / 26

Meiosis: The Process of Gamete Formation

Learn about meiosis, the process by which haploid gametes are produced, and why it is important for sexual reproduction. Understand the steps of meiosis, crossing over, and independent assortment.

marruda
Download Presentation

Meiosis: The Process of Gamete Formation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Meiosis BIO 1113/1114 Oklahoma City Community College Dennis Anderson

  2. 23 Egg and Sperm 23

  3. Terms • Haploid • One set of chromosomes • 23 for man • Diploid • Two sets of chromosomes • 46 in man • Gamete • Reproductive cell • Egg and sperm • Zygote • Fertilized egg

  4. Why are gametes haploid?If were diploid the chromosomes would double every generation • 46 • 92 • 184 • 368 • 736 • 1472

  5. Meiosis • Produces haploid gametes • 23 chromosomes

  6. Step 1 (a) Meiosis I End of interphase DNA has already duplicated

  7. Step 2 (a) Meiosis I Diploid End of interphase Prophase I Homologous chromosomes link as they condense, DNA has already duplicated Crossing over occurs

  8. Step 3 (a) Meiosis I Diploid End of interphase Prophase I Metaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate DNA has already duplicated Independent assortment occurs Crossing over occurs

  9. Step 4 (a) Meiosis I Diploid End of interphase Prophase I Metaphase I Anaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate Microtubules separate homologous chromosomes (sister chromatids remain together). DNA has already duplicated Independent assortment occurs Crossing over occurs

  10. Step 5 (a) Meiosis I Haploid Diploid End of interphase Prophase I Metaphase I Anaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate Telophase I Microtubules separate homologous chromosomes (sister chromatids remain together). DNA has already duplicated Two haploid daughter cells result from cytokinesis. Independent assortment occurs Crossing over occurs

  11. Step 6 (a) Meiosis I Meiosis II Haploid Diploid End of interphase Prophase I Metaphase I Anaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate Telophase I Microtubules separate homologous chromosomes (sister chromatids remain together). Prophase II DNA has already duplicated Two haploid daughter cells result from cytokinesis. (Brief) Independent assortment occurs Crossing over occurs

  12. Step 7 (a) Meiosis I Meiosis II Haploid Diploid End of interphase Prophase I Metaphase I Anaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate Telophase I Microtubules separate homologous chromosomes (sister chromatids remain together). Prophase II DNA has already duplicated Metaphase II Two haploid daughter cells result from cytokinesis. (Brief) Sister chromatids line up at new metaphase plate. Independent assortment occurs Crossing over occurs

  13. Step 8 (a) Meiosis I Meiosis II Haploid Diploid cytokinesis cytokinesis End of interphase Prophase I Metaphase I Anaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate Telophase I Microtubules separate homologous chromosomes (sister chromatids remain together). Prophase II DNA has already duplicated Metaphase II Two haploid daughter cells result from cytokinesis. Anaphase II Telophase II (Brief) Sister chromatids line up at new metaphase plate. Sister chromatids separate. Four haploid cells result. Independent assortment occurs Crossing over occurs

  14. Step 9 (a) Meiosis I Meiosis II Haploid Diploid cytokinesis cytokinesis End of interphase Prophase I Metaphase I Anaphase I Homologous chromosomes link as they condense, Microtubules move homologous chromosomes to metaphase plate Telophase I Microtubules separate homologous chromosomes (sister chromatids remain together). Prophase II DNA has already duplicated Metaphase II Two haploid daughter cells result from cytokinesis. Anaphase II Telophase II (Brief) Sister chromatids line up at new metaphase plate. Sister chromatids separate. Four haploid cells result. Independent assortment occurs Crossing over occurs

  15. Mitosis Metaphase Chromosomes line up in a single row.

  16. Chromosomes separate Each chromatid becomes a single chromosome

  17. Meiosis Metaphase I Chromosomes line up in a double row.

  18. Chromosomes separate Each each daughter cell gets doubled chromosomes

  19. Doubled Chromosomes Separate in Second Meiotic Division

  20. Mitosis Metaphase I Meiosis Metaphase

  21. Homologous Chromosomes • Chromosomes of the same pair • Karyotypes are usually arranged with homologous chromosomes paired together

  22. Cms 1 Cms 1 Cms 2 Cms 2 Double Filed Chromosomes • Daughter cells receive ONE of each cms pair • Independent assortment

  23. Step 1 (b) Crossing over Exchange of parts of non-sister chromatids. duplicated maternal chromosome duplicated paternal chromosome sister chromatids non-sister chromatids

  24. Step 2 (b) Crossing over Exchange of parts of non-sister chromatids. duplicated maternal chromosome duplicated paternal chromosome tetrad sister chromatids non-sister chromatids

  25. Step 3 (b) Crossing over Exchange of parts of non-sister chromatids. duplicated maternal chromosome duplicated paternal chromosome tetrad sister chromatids non-sister chromatids

  26. The End

More Related