Question

the placenta in mammal is a.allanotoic type b.yolk sac placenta c.no placenta occurs in mammal d both a and b​

Answer 1

Answer:

Placental mammals all bear live young, which are nourished before birth in the mother's uterus through a specialized embryonic organ attached to the uterus wall, the placenta. The placenta is derived from the same membranes that surround the embryos in the amniote eggs of reptiles, birds, and monotreme. mammals.