Question

1. the first chemical digestion in the human digestive system takes place where?

a. stomach
b. oral cavity
c. jejunum
d. duodenum
e. chemical digestion does not take place in any of these

Explanation:

Chemical digestion begins in the oral cavity. Saliva contains enzymes like amylase that start breaking down carbohydrates. The stomach mainly uses acid and pepsin for protein digestion (later in the process). The jejunum and duodenum are parts of the small intestine where further digestion and absorption occur (not the first site). So, the first chemical digestion is in the oral cavity.

Answer:

B. oral cavity