Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. Pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species. These two juniper species are kept separate by ________.
A) habitat isolation
B) temporal isolation
C) gametic isolation
D) behavioral isolation

Question

Quizplus · Accepted Answer

The fact that pollen grains from one species are unable to germinate and make pollen tubes on female ovules of the other species indicates that there is gametic isolation, which is a type of reproductive isolation that arises as a result of incompatible gametes (sperm and egg cells) preventing fertilization between species. Habitat isolation refers to species occupying different habitats and not coming into contact, temporal isolation refers to species having different mating periods, and behavioral isolation refers to species having different courtship behaviors that prevent mating.

Rocky Mountain Juniper (Juniperus Scopulorum) and One-Seeded Juniper (J