In the stomach, food undergoes chemical and mechanical digestion. Peristaltic contractions (mechanical digestion) churn the bolus, which mixes with strong digestive juices that the stomach lining cells secrete (chemical digestion). As food travels from your mouth into your digestive system, it's broken down by digestive enzymes that turn it into smaller nutrients that your body can easily absorb. This breakdown is known as chemical digestion.
Mutalistic Relationship <span />
A.True it gives benefits to creature it can survive reproduce and pass down traits they can evolve and become more and more sucessful
The answer to this question would be Fermentation. This is a process that releases energy when oxygen is insufficient.