Answer:
Beak shape/size or song or behavior or mechanical/chemical differences or time of mating or location on the island or primary food source differs between the Big Bird lineage and G. fortis.
Also acceptable: Description of another mechanism that prevents males and females from different populations from encountering each other/recognizing each other as potential mates.
Ionic bonds result when electrons are tranfered between atoms. Covalent bonds result when valence electrons are shared between atoms. You should be able to identify whether an ionic or covalent bond is being formed between atoms.
Answer: D) the central and peripheral nervous systems
hope this helps
This would be the nucleiod region.