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.
The ribosome, since all organisms need to synthesize proteins.
A third-degree burn would be less painful than a first- or second-degree burn involving the same body area because of the destruction of underlying pain receptors.
Nerve endings are destroyed in third-degree burns, which means that a person can no longer feel pain in that particular spot on the body. Third-degree burns are the most severe ones and cannot be treated easily - usually skin grafting or synthetic skin has to be used to replace the burnt skin.
I'm pretty sure it's Cells