Two related species of frogs appear very similar , but they have different mating calls. In addition , one species breeds in the fall and the other breeds in the spring . What mechanisms contribute to reproductive isolation of these species ?

Nh3 +02-no + h20 is unbalanced what is the balanced equation

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

Where is most of the fresh water on earth found a in the ocean b in glaciers and in ice caps c in rivers d in the soil