Opercula are absent in cartilaginous and jawless fishes and represent an evolutionary advancement seen in bony fish. how do opercula allow a bony fish to pass water over its gills while the fish remains statrionary? why would this be viewed as an adaptation?

1) what three conditions must be present for minerals to form through natural processes? 2) why are minerals considered inorganic substances? 3) how do oxides differ from other minerals that contain oxygen atoms? 4) how is a sulfide different from a sulfate? what makes native elements unique?

Each member of a class sampled a piece of ptc testing paper. thirty people sampled the chemical. twenty persons were tasters. how many had heterozygous genes? 10 20 0-20 indeterminate

Define adaptation. why do organisms adapt? give an example.