Two species interbreed occasionally and produce vigorous, fertile hybrids. When the hybrids breed with each other or with either parent species, however, the offspring are feeble or sterile. These species are affected by
A) gametic isolation.
B) reduced hybrid fertility.
C) reduced hybrid viability.
D) hybrid breakdown.

Question

Quizplus · Accepted Answer

Hybrid breakdown occurs when the first-generation hybrids are viable and fertile, but when these hybrids mate with each other or with either parent species, their offspring are feeble or sterile. This situation matches the scenario described.

Two Species Interbreed Occasionally and Produce Vigorous, Fertile Hybrids