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A Practical Approach, Second Edition=Ronald D. Ho.pdf

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Table 6.2Comparative reproductive and placental features in selected experimental mammals and humansFeature Rat Mouse Rabbit Hamster Guinea Pig Rhesus Monkey HumanEstrus cycle (days) 4–6 3–9 None 4 16 28(menstrual cycle)28(menstrual cycle)Ovulation stimulus Spontaneous Spontaneous Coitus Spontaneous Spontaneous Spontaneous SpontaneousUterus Bicornuate Bicornuate Duplex Bicornuate Bicornuate Simplex SimplexUsual no. of offspring 6–14 8–16 6–9 5–10 3–4 1 1Gestation (days) 22 19 30–32 15–16 67–68 166 266Implantation type Eccentric —earlyInterstitial — lateEccentric —earlyInterstitial — lateSuperficial Interstitial Interstitial Superficial InterstitialClassification by fetal Early Early Early Early Earlymembranes that Inverted yolk sac Inverted yolk sac Inverted yolk sac Inverted yolk sac Inverted yolk sac Chorioallantoic Chorioallantoiccontribute to placenta Definitive Definitive Definitive Definitive DefinitiveChorioallantoic Chorioallantoic Chorioallantoic Chorioallantoic ChorioallantoicPlacental shape Discoid Discoid Discoid Discoid Discoid Bidiscoid DiscoidInternal placental Labyrinthine Labyrinthine Labyrinthine Labyrinthine Labyrinthine Villous VillousstructurePlacental relation tomaternal tissuesHemotrichorial Hemotrichorial Hemodichorial Hemotrichorial Hemomonochorial Hemomonochorial HemomonochorialCOMPARATIVE FEATURES OF VERTEBRATE EMBRYOLOGY 153© 2006 by Taylor & Francis Group, LLC

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