Please help me with my science homework

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

Describe the function of the endomembrane system? what organelles are involved?

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.