Question

Three species of frogs, Rana pipiens, Rana clamitans, and Rana sylvatica, all mate in the same ponds, but they pair off correctly because they have different calls. This is a specific example of a __________ barrier, called __________.
prezygotic ... behavioral isolation
prezygotic ... temporal isolation
postzygotic ... hybrid breakdown
prezygotic ... gametic isolation
postzygotic ... mechanical isolation

Answer 1

Answer:

prezygotic ... behavioral isolation

Explanation:

Prezygotic barrier is a reproductive barrier that occurs when fertilization is prevented from occurring as a result of isolation leading to prevention of copulation, and as such there is no fusion of gametes for fertilization to take place, and eventually formation of zygote. Zygote is not formed as fertilization does not take place.

Behavioral isolation is a prezygotic reproductive barrier that prevents two or more different species to copulate together in order for fertilization to take place due to differences in behavior that is unique to each species. One of such behaviors is mating calls.

As a result of the differences in mating calls which is unique to each species of frogs mentioned in the question, only members of each species get attracted to themselves and mate with their members, thereby making it almost impossible for the three different species of frogs to mate together.

Answer 2

Answer:

The correct answer is "prezygotic ... behavioral isolation".

Explanation:

A prezygotic barrier is defined as any structure or compound that prevents that the mechanism of fertilization occurs. This is the case of the three species of frogs that even if they mate in the same ponds, they pair off correctly to each other. This is also an example of behavioral isolation, because the frogs do not interbreed even if they are closely related, because they do not have mating recognition.