Sites of Ingestion and Digestion in the Human Digestive System

Steps:

• Ingestion is the process of taking food into the body via the mouth, labeled as 1.
• Digestion involves breaking down food chemically and mechanically, starting in the mouth but primarily occurring in the stomach, labeled as 3.
• Match ingestion to position 1 and digestion to position 3 based on standard digestive anatomy.
• Select the option pairing digestion first (3) and ingestion second (1).

Why C is correct:

• C (3 1) accurately pairs digestion in the stomach with ingestion in the mouth, per the biological definition of these processes in the alimentary canal.

Why the others are wrong:

• A (1 3) reverses the sites, incorrectly placing digestion in the mouth and ingestion in the stomach.
• B (2 3) includes the esophagus (2) for ingestion, but no food intake occurs there.
• D (3 2) pairs digestion with the esophagus (2), where no digestion happens.

Final answer: C