What is a homologous structure? A. A structure with similar shape but a different use
B. A structure that is only in index fossils
C. A structure that only exists in the embryo
D. A structure that has no use in the organism

It is believed that europa, one of jupiter’s moons has an ocean beneath its surface. based on how earth’s oceans and atmosphere are believed to have formed, what can be said about europa’s supposed ocean? the arrival of in the early days of europa’s existence could have formed its ocean. it is likely that the water experienced , similar to earth. it is also possible that this water is retained beneath europa’s surface and in its atmosphere due to europa’s .