A mammal whose offspring develop inside the female's uterus; examples include deer, humans, and bears is known as what?

A mammal whose offspring develop inside the female's uterus; examples include deer, humans, and bears is known as what?

• A. Placental
• B. Marsupial
• C. Monotreme
• D. Reptile

Answer: (A)

Offspring development inside the uterus with nutrient exchange through the placenta defines placental mammals. In these animals, the embryo grows for a relatively long gestation period while connected to the mother via the placenta, which supplies nutrients and removes waste. Deer, humans, and bears are all examples of placental mammals, producing relatively mature young at birth. This differs from marsupials, which give birth to underdeveloped young that continue growing in a pouch; monotremes, which lay eggs; and reptiles, which are not mammals at all.

Offspring development inside the uterus with nutrient exchange through the placenta defines placental mammals. In these animals, the embryo grows for a relatively long gestation period while connected to the mother via the placenta, which supplies nutrients and removes waste. Deer, humans, and bears are all examples of placental mammals, producing relatively mature young at birth. This differs from marsupials, which give birth to underdeveloped young that continue growing in a pouch; monotremes, which lay eggs; and reptiles, which are not mammals at all.