what organisms need lungs
Some animals such as amphibians are able to exchange gases through their moist skin. Fish have gills while mammals, birds, and reptiles have lungs. Your respiratory system is made of your nose and mouth, a tube called the pharynx, another tube called the trachea, and your lungs. You have two lungs and the exchange of gases between the circulatory and respiratory systems happens in the lungs. Animals need oxygen (O) to survive. In fact, all organisms need oxygen to complete the process to burning glucose for fuel. Even protists and plants need oxygen, but as you become more active, you need a lot of oxygen. That's where your respiratory system comes in. It's purpose is to bring oxygen into your body.
(A large surface area: volume ratio is preferable for carrying out exchange of substances). Such large organisms need special respiratory organs such as lungs for taking in oxygen. Examples. 1  Alveoli in the lungs have a large surface area: volume ratio meaning gas exchange in humans occurs at a fast rate. 2  The filaments used in gas exchange for fish also have a large surface area: volume ratio as its surfaces are covered in lamellae. 3  This larger ratio means it is suitable for diffusion.