A long period of uterine development and gas, nutrient, and waste exchange between the mother and embryo are characteristic of _________.

0 votes
    birds
    monotremes
    marsupials
    all mammals
    placental mammals

asked May 30, 2013 in Biology by anonymous
    

1 Answer

0 votes
placental mammals
answered May 31, 2013 by Bioshare ~Top Expert~ (34,070 points)



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