1 / 24

Meiosis & Gametogenesis

Me. Meiosis & Gametogenesis. By; Amina Brucaj , Nora Hassan. What is meiosis?. Meiosis is the production of gametes, egg and sperm, through cell division. Gametes are Haploid cells meaning that the cell has one copy of each homologous chromosome. Meiosis is divided into two cell division:

inara
Download Presentation

Meiosis & Gametogenesis

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. Me Meiosis & Gametogenesis By; AminaBrucaj , Nora Hassan

  2. What is meiosis? • Meiosis is the production of gametes, egg and sperm, through cell division. Gametes are Haploid cells meaning that the cell has one copy of each homologous chromosome. • Meiosis is divided into two cell division: • 1.Meiosis 1- when alike (homologous) pairs split into two cells. First, the homologous chromosomes pair at the metaphase plate and then split as they move to the opposite poles . • 2. Meiosis 2- the replicated sister chromatids split and form chromosomes. (spread across metaphase plate, split at the poles.)

  3. Meiosis 1*GETTING READY* The nuclear envelope and nucleoli are visibly seen. DNA is synthesized.

  4. Meiosis 1*INTERPHASE I * • The nuclear envelope and nucleoli are visibly seen. • DNA is synthesized.

  5. Meiosis 1*CONDENSATION*

  6. Meiosis 1*Prophase 1 * DNA condensation takes place. The nuclear envelope disappears and the spindle fibers begin to form. The chromosomes become visible as tetrads.

  7. MEIOSIS 1*ALIGNMENT*

  8. Meiosis 1*METAPHASE 1* • The tetrads line up in the middle. • The spindle fibers are completely formed now.

  9. MEIOSIS I*SEPARATION*

  10. Meiosis 1*Anaphase 1* The tetrads pull apart and the Chromosomes each with two chromatids move toward the poles.

  11. MEIOSIS I *CLEAVING/SPLITTING*

  12. Meiosis 1*TELEOPHASE 1* *Cytokinesis* The homologous chromosomes each Reach the poles of the cell and nuclear envelopes are formed around them. Each nucleus is now a haploid cell. Cytokinesis follows to produce two Cells.

  13. MEIOSIS 2*CONDENSATION*

  14. Meiosis 2*PROPHASE II* -The nuclear envelope deteriorates -Spindle fibers being To grow.

  15. MEIOSIS 2*ALIGNMENT*

  16. Meiosis 2*METAPHASE II* -Alignment of the chromosomes across the middle of the plate( metaphase) -Attached to the spindle fibers -Single chromosme alignment

  17. Meiosis 2*SEPARATION*

  18. Meiosis 2*ANAPHASE II* -The sister chromatids split up into single chromosomes. -Pulled to opposite poles

  19. MEIOSIS 2*ClEAVING/SPLITTING*

  20. Meiosis 2*TELOPHASE II* * CYTOKINESIS* • The nuclear envelope develops around • each set of chromosomes. • -Cytokinesis occurs creating 4 haploid • daughter cells • -Haploid= 1 set of chromosomes (23) • each chromosome has 1 chromatid.

  21. Meiosis

  22. LEADS TO…

  23. Gametogenesis • Gametogenesis is the process of gamete production. Human gametes are formed through the process of meiosis; male gametes are sperm cells and female gametes are the egg cells. • Spermatogenesis • -Creation of the gametes for males, • known as sperm • - 46 single chromosomes are replicated • to form 46 pairs of sister chromatids. • - Through meisois II, 2 daughter cells form • 4 cells each containing 23 single chromosomes • maturing to form 4 haploid sperm cells .

  24. Gametogenesis • Oogenesis • - Formation of haploid cells from an original diploid cell , known as primary ooctye. • - Occurs once a month for females from puberty to menopause. • -Creation of the female gametes, known • as ovaries. • -Leads to the formation of four haploid • egg cells. • -Of the 4 daughter cells produced, 3 are • smaller than the 4th one. • - The smaller daughter cells become known • as polar bodies. • -The larger daughter cell becomes the final • product of oogenesis.

More Related