Which of the following would most likely happen if the epithelial cells in the stomach failed to produce mucus?
food leaving the stomach would only be partially digested.
gastric juice would digest the stomach lining, resulting in ulcers.
stomach ph would increase, resulting in acid reflux disease.
the cells would break down more slowly in order to protect the stomach.

not sure if this is what you'r looking for eubacteria and archaebacteria

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.