Final answer:
The natural environment where a species lives is called its habitat. Polar bears' habitat is the icy regions of the Arctic, and their white fur serves as an adaptation for hunting in this environment. With climate change impacting sea ice, polar bears are the most affected due to the loss of their primary hunting grounds.
Step-by-step explanation:
The natural environment where any species lives is called its habitat. A habitat includes all biotic and abiotic factors that are related to the use of the environment by the species. Polar bears (Ursus maritimus), for instance, are adapted to live in the icy habitats of the Arctic, where they rely on thick fur and a layer of fat to keep warm. Their white fur is an adaptation that helps them blend into their snowy and icy environment, making it easier for them to hunt seals and other prey.
Regarding the question about the impact of melting sea ice in Alaska, polar bears would be the most affected amongst the listed animals, as their hunting grounds are the sea ice from where they catch seals.