write the name of some organisms which break down the food material outside the body.

Choose a domesticated animal and consider how its digestive physiology might differ from that of its wild ancestors. (Think about differences in diet and selective pressures)

The small intestine breaks down sugars other than maltose. Lactose, for example is broken down into glucose and galactose by an enzyme called lactase.  The monosaccharides can then be absorbed by the small intestine.  If an individual does not produce enough lactase, the lactose moves into the colon and is used by bacteria to make carbon dioxide and other gasses.   Hypothesize how the gut bacteria are able to make CO2 from lactose. (2-3 sentences)

Trace the pathway of food through the human digestive system and indicate what happens in each part along the pathway.