Some aerobic organisms, such as humans, can only survive in the presence of oxygen. Other aerobic organisms, such as yeast, can also survive in the absence of oxygen, but they do so less efficiently.
In contrast to aerobic organisms, anaerobic organisms are those that do not require oxygen to survive. This includes a small number of bacteria and archaea. Anaerobic organisms use other methods to convert food into energy, such as fermentation or photosynthesis.
The requirement for oxygen is one of the key differences between aerobic and anaerobic organisms. This difference has a profound impact on the way these organisms live and reproduce. Aerobic organisms are typically found in environments where oxygen is abundant, while anaerobic organisms are typically found in environments where oxygen is scarce.
