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Embryology

  • Ahmad Wagih Abdel (Halim)
Chapter

Gametogenesis

  • The gametes originate in the yolk sac and migrate to the gonads in the form of primordial germ cells.

  • The primordial germ cells transform into either sperm or ova depending on the individual’s sex.

Meiosis (Figs. 2.12.3 )

  • Meiosis I:
    1. 1.

      This phase begins with oogonia in females and spermatogonia in males; both types of cells have 46 chromosomes and 2 NDNA.

       
    2. 2.

      Meiosis I concludes with the formation of secondary gametocytes (23, 2 N).

       
    3. 3.

      Processes occurring during meiosis I are DNA replication and crossing over.

       
    4. 4.

      Note: The centromere does not divide during meiosis I.

       

Keywords

Clinical Picture Patent Ductus Arteriosus Ventricular Septal Defect Undescended Testis Urogenital Sinus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.McLaren Regional Medical CenterFlintUSA

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