Lungs, gills and sometimes skin.
Lungs
Animals inhale air in order to obtain the oxygen they use for extracting energy from food
Eagles obtain oxygen through breathing, just like other animals. They use their respiratory system to take in oxygen from the air and transfer it to their bloodstream, where it is delivered to cells throughout their body.
any animal that is on land at some point in its life obtain oxygen the same exact way we do. the only animal that obtains oxygen in a different way is the fish and it obtains its oxygen by filtering the water it swims through between its gills.
Animals breathe in oxygen in the air.
a snorkel
Pterodactyls do not obtain oxygen at this time because they are extinct. While they existed, they probably obtained oxygen in the same way that birds today obtain it through the use of lungs.
Animals do not use up all the oxygen in the atmosphere because plants produce oxygen. When they breathe, plants inhale carbon dioxide (which is what animals breathe out) and exhale oxygen (which is what animals breathe in).
Oxygen is used in cellular respiration to obtain ATP, which is used for energy.
For starters, algae are plants. Plants never use oxygen. Animals use oxygen in the process of respiration. Decomposers use oxygen in the process of respiration when decomposing plants and animals including algae.
they use their lungs to breath
its trunk