Introduction to Digestion and Nutrients

Based on the information provided: Which statement best explains why drinking a relatively large amount of liquid is reasonable for humans? Choose the most accurate option.

• Most of the body’s mass is made of bone, which requires frequent hydration.

• About 60–70% of total body weight is water, so substantial fluid intake aligns with our composition.

• Only the digestive tract contains water, so extra drinking replaces losses.

• Water makes up less than 10% of body weight, so we must drink more to compensate.

The digestive system’s primary role is described as allowing the body to use nearly everything eaten and drunk while wasting very little. Which option best matches this function?

• It stores nutrients long-term without processing them.

• It breaks down food and drink to enable absorption of useful components, minimizing waste.

• It removes water from the body to keep weight stable.

• It converts all food directly into fat for energy reserves.

A student plans a balanced meal using the nutrient groups shown (Carbohydrates, Proteins, Lipids, Vitamins and Minerals). Which choice best demonstrates strategic planning aligned with these categories?

• Selecting only carbohydrate-rich foods to maximize quick energy.

• Combining whole grains, lean meats or legumes, healthy oils or nuts, and a variety of fruits and vegetables.

• Avoiding lipids entirely and eating only protein and vitamins.

• Focusing on high-fat foods to reduce waste in the digestive system.

Which statement best describes the primary role of the digestive system?

• It converts food into forms that cells can use.

• It stores nutrients without altering them.

• It circulates oxygen directly to cells.

• It produces hormones to regulate heart rate.

Which process is correctly paired with its description?

• Ingestion—putting food into the body.

• Mechanical digestion—breaking chemical bonds in nutrients.

• Chemical digestion—chewing food into smaller pieces.

• Egestion—absorbing nutrients into blood.

Which statement distinguishes chemical digestion from mechanical digestion?

• Chemical digestion breaks chemical bonds to yield basic nutrients; mechanical digestion only reduces food into smaller pieces.

• Chemical digestion occurs only in the mouth; mechanical digestion occurs only in the stomach.

• Mechanical digestion produces glucose and fatty acids; chemical digestion produces smaller food pieces.

• Mechanical digestion absorbs nutrients; chemical digestion egests waste.

In the context of the digestive processes, which sequence shows a logical order from intake to removal?

• Ingestion → Mechanical digestion → Chemical digestion → Absorption → Egestion

• Mechanical digestion → Ingestion → Absorption → Chemical digestion → Egestion

• Absorption → Chemical digestion → Egestion → Ingestion → Mechanical digestion

• Egestion → Absorption → Ingestion → Chemical digestion → Mechanical digestion

Refer to the diagram labeled “Protein Building Blocks.” What are the small colored units that make up a protein chain called?

• Amino acids

• Fatty acids

• Glucose molecules

• Mineral ions

Based on the idea of chemical digestion breaking food into basic units, which product would result from the chemical digestion of proteins?

• Amino acids

• Fat droplets

• Glucose

• Mineral salts

Based on the description provided, which statement best defines absorption in the digestive system?

• Movement of undigested food from the large intestine to the rectum

• Movement of the basic units of digested food out of the small intestine into the blood

• Storage of feces in the rectum before elimination

• Mechanical breakdown of food in the mouth