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25 Cards in this Set
- Front
- Back
What happens in the absence of the SRY gene?
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Primordial cells develop into oogonia
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What separates oogonia from spermatogonia in terms of developmental plan.
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Oogonia proliferate (7Mc) and then loose mitotic potential. Spermatogonial maintain mitotic potential throughout adulthood.
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Could PGCs form teratomas?
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Yes
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What are teratomas?
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Benign tumors containing cells of multiple lineages. Probably formed by PGCs that do not remain in GR.
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What aspect of PGCs enable them to form teratomas?
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Pluripotency -> multiple lineages
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Briefly descripe spermatogenesis
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Spermatogonium (2n-46)-> 1o Spermatocyte (2N-46)-> 2o Spermatocyte (N-23) -> Spermatids (N-23) -> Spermatozoids (N-23)
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What role do Sertoli cells play?
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Supportive; protective barrier and nutrient supply
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Where is the glycoprotein coat added?
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Epidydimis
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What is capacitation?
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Refers to the biochemical changes occurring in the sperm that enable it to fertilize the egg.
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Where does it occur?
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In the female reproductive tract.
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Briefly list the steps of oogenesis
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Oogonium (2N-46,m) -> 1o Oocyte (2N-46,me1-long) -> 2o Oocyte (N-23,me2-metII-fert) -> Ovum (N-23)
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How does LH surge affect the follicle?
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-Increase hyaluronan -> swelling
- MMP degrade surrounding tissue causing rupture of follicle |
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What can we learn by the presence of polar bodies?
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Developmental stage of oocyte. [Remember germ cell produces a single mature oocyte]
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Why are polar bodies smaller?
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Uneven distribution of cytoplasm b/w polar bodies and mature oocytes.
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Where is fertilization most like to occur?
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Ampullary region of Fallopian tube.
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When does cleavage occur?
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~1 day
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When does the morula form?
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~ 3 days
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When does the blastocyst form?
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~ 4 days
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When does implantation occur?
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~ 6 days
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Give the timeline of fertilization to implantation
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Fertilzation -> Cleavage (D1) -> Morula (D3) -> Blastocyst (D4) -> Implantation (D6)
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Name the layers of the mature ovum
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Corono radiata
Zona pellucida (ZP-1,2,3) Plasma membrane (Cortical granules loctated underneath) |
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How do sperm navigate to the mature ovum?
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Progesterone release by the corona radiata direct sperm; Triggers Ca2+ entry. Receptor - CatSper2
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What happens when sperm cells meet the egg?
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- Penetration of corona
- Binding to ZP3 activating acrosome. - Zona rxn by sperm binding to egg PM -> Ca2+ release -> cortical granule release. - Sperm processing - Pronucleus formation |
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What initiates the acrosome rxn?
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Sperm head binding to ZP-3
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What is the purpose of the Ca2+ release -> cortical granule release after the sperm reaches the egg PM?
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Blocks entry of other sperm cells. (Inh polyspermy)
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