One fish species occurs by itself in several nearby lakes (Lakes A, B, C, D, ... M). The other occurs by itself in other lakes (Lakes N, O, P, Q, ... Y). However, they co-occur in lake Z, but do not interbreed (one breeds in the spring in the lake itself, and the other breeds in streams feeding the lake in the fall.) Both species have several autapomorphies. Your initial hypothesis is these species arose through:

A) Phylogenetic speciation
B) Sympatric speciation
C) Allopatric speciation
D) No answer text provided.

Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. the chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. the chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production c. free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone select the best answer from the choices provided

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.