What helps a frog breathe underwater?

Answer 1

Frogs use lungs to breath on land. When they are tadpoles they have just gills but as they grow they develop lungs just like they develop legs. When most frogs are full grown, they have lungs and gills so they can breath in or out of water.

Answer 2

Frogs use their GILLS to stay under water for a long period of time. Frogs still alive to come back up to the surface to get more air in their lungs in order to stay alive and last under water for a long time.

Answer 3

stolen from wikipedia:

The skin of a frog is permeable to oxygen and carbon dioxide, as well as to water. There are a number of blood vessels near the surface of the skin. When a frog is underwater, oxygen is transmitted through the skin directly into the bloodstream. On land, adult frogs use their lungs to breathe. Their lungs are similar to those of humans, but the chest muscles are not involved in respiration, and there are no ribs or diaphragm to support breathing. Frogs breathe by taking air in through the nostrils (which often have valves which close when the frog is submerged), causing the throat to puff out, then compressing the floor of the mouth, which forces the air into the lungs. In August 2007 an aquatic frog named Barbourula kalimantanensis was discovered in a remote part of Indonesia. The Bornean Flat-headed Frog (B. kalimantanensis) is the first species of frog known to science without lungs.

Frogs are known for their three-chambered heart, which they share with all tetrapods except birds, crocodilians and mammals. In the three-chambered heart, oxygenated blood from the lungs and de-oxygenated blood from the respiring tissues enter by separate atria, and are directed via a spiral valve to the appropriate vessel-aorta for oxygenated blood and pulmonary artery for deoxygenated blood. This special structure is essential to keeping the mixing of the two types of blood to a minimum, which enables frogs to have higher metabolic rates, and to be more active than otherwise.

Answer 4

skin

Answer 5

Lungs.