Need help with oogenesis question

  1. My A&P final is coming up on Thursday. In one of the essay questions, I'll be asked to outline the events of oogenesis and when they occur in the female (no problem), including all of the stages from stem cell to production of the ovum (still no problem), and to indicate at each step whether the cells formed are haploid or diploid (problem!).

    Can anyone direct me to a simple explanation online? I've had no luck finding one, and Martini's explanation is not sinking in. (I'm so ready for a vacation at this point that I'd get more benefit from beating myself with a copy of Martini.)

    Thanks for any help you can provide.
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  2. 4 Comments

  3. by   live_crow
    http://faculty.sunydutchess.edu/Scal.../Oogenesis.jpg

    This diagram has haploid/diploid marked. Oogenesis is basically the development of haploid cells from an original diploid cell, called a primary oocyte, through meiosis.

    So if diploid cell = 2n, and haploid cell = n, think that mom has 2n cells. She needs to split these so that each ovum only has n, then n is added from sperm at fertilization to make 2n baby. sorry, that's very simplistic, but it made it easier for me to understand when I studied this!
    Last edit by live_crow on Dec 16, '06
  4. by   mixyRN
    This site should help you out. I just love wikipedia!
    Oogenesis - Wikipedia, the free encyclopedia
  5. by   trepinCT
    just be careful with using that site because they are input and edited without anyone making sure the info is valid.
  6. by   jov
    Quote from Freedom42
    indicate at each step whether the cells formed are haploid or diploid (problem!).
    mostly remember haploid cells produce haploid cells and diploid cells produce diploid cells, except in fertilization of course where two haploid cells produce a diploid cell.

    In summary:
    Mitosis produces two daughter cells that are identical to the parent cell. If the parent cell is haploid (N), then the daughter cells will be haploid. If the parent cell is diploid, the daughter cells will also be diploid.

    N N
    2N 2N
    This type of cell division allows multicellular organisms to grow and repair damaged tissue.
    Meiosis produces daughter cells that have one half the number of chromosomes as the parent cell.

    2N N
    Meiosis enables organisms to reproduce sexually. Gametes (sperm and eggs) are haploid.
    Meiosis is necessary in sexually-reproducing organisms because the fusion of two gametes (fertilization) doubles the number of chromosomes.

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