BIOL 121 | BIOL121 Module 1: Nutrition Updated
and Latest Questions and Correct Answers with
Rationale - Portage Learning
1. Which of the following is defined as a chemical substance in food that contributes to
health?
A. Enzyme
B. Hormone
C. Nutrient
D. Calorie
Correct Answer: C
Expert Explanation: Nutrients are essential substances obtained from food that the body
uses for energy, growth, and maintenance. They are categorized into six main classes
including carbohydrates, lipids, proteins, vitamins, minerals, and water. A substance is
considered essential if its omission leads to a decline in biological function. Once the
missing substance is replaced, those biological functions are restored. This question tests
the foundational definition of nutrition science.
2. Which macronutrient provides the most energy per gram?
A. Carbohydrates
B. Proteins
C. Fats (Lipids)
D. Alcohol
Correct Answer: C
Expert Explanation: Fats provide 9 kilocalories per gram, making them the most energy-
dense macronutrient. In contrast, carbohydrates and proteins provide only 4 kilocalories
per gram. Alcohol provides 7 kilocalories per gram but is not considered an essential
nutrient. Understanding energy density is crucial for managing weight and overall energy
balance. This differentiation helps in calculating the total caloric content of various food
items.
3. A substance that the body cannot produce on its own or in sufficient quantities is called
a(n):
A. Phytochemical
B. Non-essential nutrient
C. Essential nutrient
,D. Macronutrient
Correct Answer: C
Expert Explanation: Essential nutrients must be obtained through the diet because the
body lacks the machinery to synthesize them. If these nutrients are missing, specific
deficiency symptoms will eventually manifest. Non-essential nutrients can be made by the
body even if they are not consumed. Phytochemicals are plant-derived compounds that
may provide health benefits but are not currently classified as essential. Distinguishing
between these categories is a core concept in nutritional biology.
4. What is the primary function of carbohydrates in the human body?
A. To build muscle tissue
B. To regulate body temperature
C. To act as the primary storage of vitamins
D. To provide a primary source of fuel for the brain and body
Correct Answer: D
Expert Explanation: Carbohydrates are the preferred energy source for the central
nervous system and red blood cells. They are broken down into glucose, which provides
immediate energy for cellular processes. While proteins can provide energy, their primary
role is tissue repair and growth. Lipids are the main storage form of energy and also assist
in temperature regulation. Recognizing the primary role of each macronutrient helps in
understanding metabolic priorities.
5. Which of the following is a micronutrient?
A. Lipid
B. Protein
C. Vitamin C
D. Water
Correct Answer: C
Expert Explanation: Micronutrients are required by the body in small amounts, typically
milligrams or micrograms. This category includes all vitamins and minerals which act as
cofactors for metabolic reactions. Macronutrients like proteins and lipids are required in
much larger gram quantities. Water is required in large amounts but is not classified as a
micronutrient or macronutrient in the traditional sense. This classification is based on the
quantity required rather than the importance of the nutrient.
6. What term describes the physiological drive to find and eat food?
A. Hunger
, B. Satiety
C. Appetite
D. Binging
Correct Answer: A
Expert Explanation: Hunger is an internal, biological drive for food regulated by internal
cues like blood glucose and hormones. Appetite is an external, psychological desire to eat
often triggered by sensory cues or emotions. Satiety is the state of feeling full after eating,
which inhibits the drive to eat further. Understanding the difference between hunger and
appetite is key to managing overconsumption. These regulatory mechanisms ensure the
body receives adequate energy to function.
7. Which organ is the primary site for the digestion and absorption of nutrients?
A. Stomach
B. Small Intestine
C. Large Intestine
D. Esophagus
Correct Answer: B
Expert Explanation: The small intestine is uniquely structured with villi and microvilli to
maximize surface area for absorption. While the stomach begins protein digestion, very
little absorption occurs there. The large intestine primarily absorbs water, electrolytes, and
some vitamins produced by bacteria. The esophagus acts simply as a conduit to move food
from the mouth to the stomach. Most chemical digestion is completed within the
duodenum and jejunum of the small intestine.
8. If a snack contains 10 grams of fat, how many kilocalories from fat does it provide?
A. 40 kcal
B. 70 kcal
C. 100 kcal
D. 90 kcal
Correct Answer: D
Expert Explanation: To find the kilocalories from fat, you multiply the grams of fat by 9. In
this calculation, 10 grams times 9 kcal/g equals 90 kilocalories. This formula is standard for
determining the energy contribution of lipids in any food product. Protein and
carbohydrates would only contribute 40 kcal for the same weight. Calculating caloric
distribution is a fundamental skill in nutritional assessment.
and Latest Questions and Correct Answers with
Rationale - Portage Learning
1. Which of the following is defined as a chemical substance in food that contributes to
health?
A. Enzyme
B. Hormone
C. Nutrient
D. Calorie
Correct Answer: C
Expert Explanation: Nutrients are essential substances obtained from food that the body
uses for energy, growth, and maintenance. They are categorized into six main classes
including carbohydrates, lipids, proteins, vitamins, minerals, and water. A substance is
considered essential if its omission leads to a decline in biological function. Once the
missing substance is replaced, those biological functions are restored. This question tests
the foundational definition of nutrition science.
2. Which macronutrient provides the most energy per gram?
A. Carbohydrates
B. Proteins
C. Fats (Lipids)
D. Alcohol
Correct Answer: C
Expert Explanation: Fats provide 9 kilocalories per gram, making them the most energy-
dense macronutrient. In contrast, carbohydrates and proteins provide only 4 kilocalories
per gram. Alcohol provides 7 kilocalories per gram but is not considered an essential
nutrient. Understanding energy density is crucial for managing weight and overall energy
balance. This differentiation helps in calculating the total caloric content of various food
items.
3. A substance that the body cannot produce on its own or in sufficient quantities is called
a(n):
A. Phytochemical
B. Non-essential nutrient
C. Essential nutrient
,D. Macronutrient
Correct Answer: C
Expert Explanation: Essential nutrients must be obtained through the diet because the
body lacks the machinery to synthesize them. If these nutrients are missing, specific
deficiency symptoms will eventually manifest. Non-essential nutrients can be made by the
body even if they are not consumed. Phytochemicals are plant-derived compounds that
may provide health benefits but are not currently classified as essential. Distinguishing
between these categories is a core concept in nutritional biology.
4. What is the primary function of carbohydrates in the human body?
A. To build muscle tissue
B. To regulate body temperature
C. To act as the primary storage of vitamins
D. To provide a primary source of fuel for the brain and body
Correct Answer: D
Expert Explanation: Carbohydrates are the preferred energy source for the central
nervous system and red blood cells. They are broken down into glucose, which provides
immediate energy for cellular processes. While proteins can provide energy, their primary
role is tissue repair and growth. Lipids are the main storage form of energy and also assist
in temperature regulation. Recognizing the primary role of each macronutrient helps in
understanding metabolic priorities.
5. Which of the following is a micronutrient?
A. Lipid
B. Protein
C. Vitamin C
D. Water
Correct Answer: C
Expert Explanation: Micronutrients are required by the body in small amounts, typically
milligrams or micrograms. This category includes all vitamins and minerals which act as
cofactors for metabolic reactions. Macronutrients like proteins and lipids are required in
much larger gram quantities. Water is required in large amounts but is not classified as a
micronutrient or macronutrient in the traditional sense. This classification is based on the
quantity required rather than the importance of the nutrient.
6. What term describes the physiological drive to find and eat food?
A. Hunger
, B. Satiety
C. Appetite
D. Binging
Correct Answer: A
Expert Explanation: Hunger is an internal, biological drive for food regulated by internal
cues like blood glucose and hormones. Appetite is an external, psychological desire to eat
often triggered by sensory cues or emotions. Satiety is the state of feeling full after eating,
which inhibits the drive to eat further. Understanding the difference between hunger and
appetite is key to managing overconsumption. These regulatory mechanisms ensure the
body receives adequate energy to function.
7. Which organ is the primary site for the digestion and absorption of nutrients?
A. Stomach
B. Small Intestine
C. Large Intestine
D. Esophagus
Correct Answer: B
Expert Explanation: The small intestine is uniquely structured with villi and microvilli to
maximize surface area for absorption. While the stomach begins protein digestion, very
little absorption occurs there. The large intestine primarily absorbs water, electrolytes, and
some vitamins produced by bacteria. The esophagus acts simply as a conduit to move food
from the mouth to the stomach. Most chemical digestion is completed within the
duodenum and jejunum of the small intestine.
8. If a snack contains 10 grams of fat, how many kilocalories from fat does it provide?
A. 40 kcal
B. 70 kcal
C. 100 kcal
D. 90 kcal
Correct Answer: D
Expert Explanation: To find the kilocalories from fat, you multiply the grams of fat by 9. In
this calculation, 10 grams times 9 kcal/g equals 90 kilocalories. This formula is standard for
determining the energy contribution of lipids in any food product. Protein and
carbohydrates would only contribute 40 kcal for the same weight. Calculating caloric
distribution is a fundamental skill in nutritional assessment.
