Select the correct text in the passage. Pick out the sentences that correctly describe marine mammals.
Marine mammals are endothermic, or warm-blooded. Species such as whales breathe air though their gills. They have a thick layer of blubber
that helps maintain buoyancy. They can stay underwater indefinitely. Dolphins are a type of toothed whale. Baleen whales feed on large fish
and sometimes seals.

Marine mammals are endothermic. I think that's the correct answer 'cause they can produce their own body heat (which therefore means that they are warm-blooded) and they can keep at a stable temperature even in harsh conditions. Plus, whales don't have gills b/c they are mammals (and mammals don't have gills), not all mammals have blubber (it's mainly penguins and seals), marine mammals can stay underwater for a long amount of time...but they eventually need to come up for air, and baleen acts like a "filter"; it "filter" and separates the water from the krill/microorganisms.

Hope this helps! :)

a

explanation:

you know they are heterozygous for a trait because they have it as jj or jj.