Whales use the mouth and blowhole to breathe.
Gills.............
pretty sure it's gills :)
The organ responsible for breathing is your lungs.
Yes, it is, though debatable, the nose could also be called a passageway, this "organ" is used in the respiratory system, and the process of breathing.
lungs
Yes!
Just like humans, squirrels contain lungs, the major breathing organ in the respiratory system.
Organ
lungs
Gills
Gills
Lungs