Question

the main function of the human digestive system is to
1 rid the body of cellular waste materials
2 process organic molecules so they can enter cells
3 break down glucose in order to release energy
4 change amino acids into proteins and carbohydrates

Explanation:

1. Option 1: Removing cellular waste is the function of the excretory system (e.g., kidneys), not the digestive system.
2. Option 2: The digestive system breaks down complex organic molecules (like carbohydrates, proteins, fats) into simpler forms (e.g., glucose, amino acids, fatty acids) that can be absorbed and enter cells. This matches the main function of digestion and absorption.
3. Option 3: Breaking down glucose to release energy is cellular respiration, occurring in cells (mitochondria), not the digestive system.
4. Option 4: Amino acids are used to build proteins, and the digestive system breaks down proteins into amino acids (not the reverse), and it doesn’t convert amino acids to carbohydrates.

Answer:

1. process organic molecules so they can enter cells