Two juniper trees (Juniperus scopulorum and J. monosperma) have overlapping geographic 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. Which of the following isolating mechanisms keeps the two species separate?
A) habitat isolation
B) temporal isolation
C) gametic isolation
D) behavioral isolation

Question

Quizplus · Accepted Answer

Gametic isolation is a prezygotic barrier where the gametes (e.g., pollen and ovules in plants) of two different species meet but are unable to fuse to form a zygote. In this case, the pollen grains from one juniper species cannot germinate on the ovules of the other species, preventing fertilization and thus maintaining species separation.

Two Juniper Trees (Juniperus Scopulorum and J