Where does embryonic development occur in mammals?
1 Answer
Mammals are separated into three groups. 1. Prototheria (before gestation) - egg laying mammals, 2. Metatheria (middle gestation) - pouched mammals and 3. Eutheria (true gestation) - live birth from uterus.
Explanation:
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In Prototherian mammals embryonic development occurs in egg. They’re egg laying mammals (oviparous).
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In Metatherian mammals embryo starts it’s development within the mother’s uterus, supported by a short-lived placenta. A marsupial is born very early in its development. It complete it’s embryonic development while nursing in a maternal pouch called marsupium. They’re viviparous.
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In Eutherian mammals embryo complete its embryonic development in uterus, joined to the mother by placenta. Eutherians have a longer period of pregnancy when compared to metatherians. They’re viviparous.
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