because they can breathe through their skin
Obviously not.
It is neccesarily because frogs are amphibians and therefore to be on land they need lungs to breathe
The blue whale has the largest lungs but the harbor porpoise has thlargest lung capacity.
They are amphibians. They need the moisture on their skin. It also need air to breathe.
YES
The lungfish has both gills and lungs.
An artery which goes to the lungs, and the skin, making it possible for the frog to breathe through the skin, and not the lungs.
They are born with gills, but develop lungs in metamorphosis. Even when they have lungs, they still need water or else they will dry up and die.
With lungs
The color of frog's lungs are a purplish brown.
Adult Bull Frog
frog and birds