Alcohol fermentation produces carbon dioxide gas as a by-product, and this is why alcohol fermentation is more suitable for baking. Alcohol fermentation occurs when breads are made. The carbon dioxide gas is what creates tiny air bubbles within the dough and makes bread be the light consistency we are used to. In contrast, bread made without yeast (alcohol fermentation) is very flat.
Explanation: The definition of mutualism states " interaction between two or more species where each species has a benefit". The bird is getting food from the insects and the horse is getting the insects removed. Both are benefited.
