Which of the Following Is Not Considered to Be a Primary

question 113

Multiple Choice

Which of the following is not considered to be a primary organ in the human digestive system?

• A)esophagus
• B)mouth
• C)liver
• D)stomach
• E)small intestine

---

Definitions:

NADH

Nicotinamide adenine dinucleotide (reduced form), a coenzyme found in all living cells that plays a critical role in energy production through oxidation-reduction reactions.

Fermentation

Anaerobic breakdown of glucose that results in a gain of two ATP and end products such as alcohol and lactate; occurs in the cytoplasm of cells.

Muscles

Tissues in the body that can contract, enabling movement and force generation.

Oxygen

A chemical element (O) essential for most life forms on Earth; it participates in respiration and forms part of water molecules.