Flower A blooms in June while flower B, a close relative of A, blooms in August. A researcher is raising a population of flower B in a controlled growth chamber. Over time the researcher manipulated the day length in the growth chamber and eventually manages to induce some individuals of flower B to bloom in June. The researcher finds that she can cross these individuals with flower A individuals and they produce viable, fertile offspring. What can she conclude about flower A and flower B?
A)A and B aren't a good example of separate species.
B)A and B are genetically incompatible.
C)A and B are temporally reproductively isolated from each other.
D)The fact that B's blooming time can be manipulated suggests it should not be regarded as a species distinct from A.
E)A and B are not pre-zygotically isolated from one another.

Question

Quizplus · Accepted Answer

The fact that flower A blooms in June while flower B blooms in August suggests that they are temporally reproductively isolated from each other. However, the researcher was able to manipulate the day length in the growth chamber and induce some individuals of flower B to bloom in June. This suggests that the difference in blooming time is not due to genetic incompatibility between A and B, and that they are not pre-zygotically isolated from one another. The fact that the crosses between the June-blooming individuals of B and A produced viable, fertile offspring suggests that A and B are not a good example of separate species but rather a case of sub-species or ecotypes.

Flower a Blooms in June While Flower B, a Close