Think about the animals in an arctic ecosystem. How would
those animals adapt over time if
global temperatures rise over the
next several hundred years?

How does the author's purpose in this passage differ from an author writing about her personal struggle living with asthma?

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.