Two species of frog mate in the same pond. One breeds in early summer and one in late summer. This is an example of what kind of reproductive isolation?

A. pre-zygotic, behavioral isolation
B. pre-zygotic, temporal separation
C. pre-zygotic, ecological separation
D. post-zygotic, temporal separation
E. post-zygotic, ecological separation

Pre-zygotic, temporal separation

Explanation:

Reproductive isolation mechanism is of two types:

Prezygotic mechanism isolation occurs before fertilization and helpful in preventing formation of fertile offspring.

In frog external fertilization occurs. In the external fertilization, eggs and sperms are released in water and fertilization occur outside the water.

Prezygotic isolating mechanisms may include behavioral isolation, temporal isolation, mechanical isolation, gametic isolation and habitat isolation.

Temporal separation in reproduction is the sexual activity in the same geographical range but in different periods.

Therefore, the given reproductive isolation is pre-zygotic, temporal separation.

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.

the correct answer is c