What type of respiration occurs without the presence of oxygen?

Anaerobic respiration is a metabolic process that occurs in the absence of oxygen. During anaerobic respiration, cells convert glucose into energy through a process that does not rely on oxygen as the final electron acceptor. This type of respiration is often used by certain types of microorganisms and in muscle cells during intense exercise when oxygen supply is limited.

The primary products of anaerobic respiration can include lactic acid in animals or ethanol and carbon dioxide in yeast, depending on the organism. This process typically yields less energy compared to aerobic respiration, which requires oxygen and produces more ATP (adenosine triphosphate) per glucose molecule.

In contrast, aerobic respiration requires oxygen for the complete oxidation of glucose, resulting in a higher energy yield and producing carbon dioxide and water as byproducts. Oxidative processes generally refer to reactions involving oxygen, and cellular respiration encompasses both aerobic and anaerobic pathways. However, since the question specifically asks for respiration that occurs without oxygen, anaerobic respiration is the correct response.