Final answer:
Ingestion is the process of taking in food through the mouth, while digestion is the complex breakdown of this food into small, absorbable nutrient molecules that occur throughout various organs of the digestive system.
Step-by-step explanation:
Ingestion and digestion differ in their roles in the process of utilizing food for energy and nutrients. Ingestion is the act of taking in food through the mouth. Once in the mouth, mechanical digestion begins with mastication, where teeth, saliva, and tongue prepare food into a bolus. Following ingestion, digestion refers to the breakdown of food into usable components and includes both mechanical and chemical processes. Mechanical digestion continues in the stomach, with food being physically broken down into smaller pieces, while chemical digestion involves enzymes breaking down complex food molecules into simpler nutrient molecules that the body can absorb.
Digestion encompasses both mechanical and chemical digestion, which occur in various parts of the digestive system, including the mouth, stomach, and predominantly the small intestine. After the process of chemical digestion, absorption occurs, allowing the digested nutrient molecules to enter the bloodstream and nourish the body's cells. In contrast, ingestion is solely the intake of food into the mouth before any form of digestion has started.
The correct answer to how ingestion and digestion differ is: c) Ingestion is the intake of food into the mouth; digestion involves the breakdown of food into usable components.