Would it matter if tigers became extinct? Why do lions have manes? Why do we have red blood cells?

Some of the best interview questions do not have a 'right' or a 'wrong' answer, and can potentially lead off in all sorts of different directions. It's much more about how people approach the problem/question, and how they defend their stance. Are you able to have a discussion and state your thoughts clearly? Are you able to use information from what you have learned in school and college and apply it elsewhere?