Answer:
Herbivorous animals are unable to feed and end up migrating to other regions in search of food.
Explanation:
The tundra is a type of vegetation composed almost exclusively of mosses and lichens. This type of vegetation is found in regions with a polar climate. It is important to note that the tundra has a very fast vegetative cycle. That's because it freezes quickly and can be covered with ice all winter. This ends up modifying the lives of some animals that feed on this vegetation. These animals end up with unavailability of food and need to migrate to others in search of food.
On number one you could say dirt seeing as dirt is another word for earth because it makes up earth
Bivalves are protostomes, as they belong the to phyla Protostomia. They are freshwater/marine molluscs, whose body is covered by a protecting shell. They do not have a head, and some of their examples include oysters, clams, mussels etc.