No. Whales are placental mammals.
No. The whale is a placental marine mammal; the platypus is a semi-aquatic monotreme, or egg-laying mammal.
No, they are a marsupial and not a monotreme. There are only 2 members in the monotreme category which are the echidna and the platypus.
A platypus is a monotreme.
A monotreme is a mammal that lays eggs.
The echidna is a monotreme which eats ants.
That is the correct spelling of "monotreme" (a mammal that lays eggs).
The platypus is a monotreme mammal.
Yes, there is. The echidna is also a monotreme.
The reproductive system of a monotreme empties into the cloaca.
Yes a monotreme does have a backbone because it is a type of mammal and a mammal is a vertebrate.
No.
A Duck-billed Platypus is an Australian example of a monotreme, a mammal that lays eggs.