Answer:
1. e. Hybrid performance
2. d. Zygote death
3. a. Gametic isolation
4. f. Ecological isolation
5. g. Behavioral isolation
Explanation:
Hybrid performance is a postzygotic isolation mechanism associated with the ability to produce hybrid offspring, which are adaptively less fit than their progenitors (for example, in this case, hydric stress is a limiting factor for the viability of the hybrids). Zygote death is another postzygotic barrier where the zygote parents' genes fight one another and thus impair the development of the hybrid zygote, causing its death. Gametic isolation is a prezygotic isolation mechanism associated with the incompatibility between female and male gametes (i.e., egg and sperm in animals), which join to form a viable zygote. Ecological isolation, also known as habitat isolation, is a reproductive prezygotic barrier caused by the separation of organisms because they live in different areas or have different ecological/ environmental requirements. Finally, behavioral is another prezygotic barrier where closely related species have different mating rituals. Behavioral isolation is a common practice in many species of invertebrates (such as, for example, arachnids).