Answer:
The given blank can be filled with post.
Explanation:
A mechanism, which prevents the species from mating with others is termed as reproductive isolation. It is further differentiated into pre-zygotic and post-zygotic isolation. The phenomenon of prezygotic isolation inhibits the eggs to get fertilize, while the postzygotic isolation inhibits the generation of fertile offspring.
The mechanisms of prezygotic isolation comprise mating seasons, habitat isolation, gamete isolation, mechanical isolation, and behavioral isolation. On the other hand, postzygotic mechanisms comprise hybrid sterility, hybrid inviability, and hybrid breakdown. Thus, the given case is an example of post-zygotic isolation.