Which group includes bat and whale as examples?

Which group includes bat and whale as examples?

• A. Monotremes
• B. Marsupials
• C. Placental mammals
• D. Reptiles

Answer: (C)

Bats and whales are grouped as placental mammals because their young develop inside the mother's uterus and are nourished through a placenta during a lengthy gestation. This placenta-and-uterus connection allows the offspring to grow considerably before birth, which is a hallmark of placental mammals. Monotremes lay eggs, so they don’t share this in-utero development, and marsupials give birth to very undeveloped young that finish growing in a pouch rather than inside the uterus. Reptiles are not mammals at all. So the best group for both is placental mammals.

Bats and whales are grouped as placental mammals because their young develop inside the mother's uterus and are nourished through a placenta during a lengthy gestation. This placenta-and-uterus connection allows the offspring to grow considerably before birth, which is a hallmark of placental mammals. Monotremes lay eggs, so they don’t share this in-utero development, and marsupials give birth to very undeveloped young that finish growing in a pouch rather than inside the uterus. Reptiles are not mammals at all. So the best group for both is placental mammals.