Monotremes are mammals which lay eggs rather than give birth, therefore a seal is not a monotreme.
All seals are mammals, and mammals (apart from the monotremes) have 'babies', they do not lay eggs.
Very, very tenuously. Seals and spiny anteaters (echidnas) are both mammals. They are not, however, even the same type of mammals. Seals are placental mammals and echidnas are monotremes (egg-laying mammals).
Platypuses are only related to seals and otters in that they are all semi-aquatic mammals. Even there, the similarity is flimsy, because seals and otters are placental mammals, whereas platypuses are monotremes, or egg-laying mammals, one of only two types of such animals in the world.
Yes, monotremes are real.
No a Blue Whale is Not a monotremes.
Monotremes never eat their young.
Monotremes are egg laying mammals, the platypus and the echidna are the only two monotremes.
Eutherians and monotremes are in the phylum Chordata.
Monotremes are mammals; therefore they have lungs, not gills.
No, monotremes do not have short internal development.
Monotremes are unique for being egg laying mammals.
No: dolphins are placental mammals. The only monotremes are platypuses and echidnas.