Page 1 of 115
BIOLOGY MCB3023 HESI A2 BIOLOGY RATED
A+
COMPLETE PRACTICE QUESTION BANK
LATEST 2026-2027 ACADEMIC YEAR
ITSJEREGUIDES
# SECTION I: CHEMISTRY OF LIFE & BIOLOGICAL MOLECULES
**1. Why is polarity considered the most important characteristic of water for biological
systems?**
A) The results of polarity are covalent bonding, a low specific heat value, and its versatile
solvent properties
B) The results of polarity are ionic bonding, a high specific heat value, and its versatile solvent
properties
*C) The results of polarity are hydrogen bonding, a high specific heat value, and its versatile
solvent properties*
D) The results of polarity are hydrogen bonding, a low specific heat value, and its versatile
solvent properties
**Rationale:** Water's polarity leads to hydrogen bonding, which gives water a high specific
heat value (allowing it to resist temperature changes) and makes water a versatile solvent. These
properties are essential for biological systems as they enable temperature regulation and serve as
the medium for biochemical reactions .
---
,Page 2 of 115
**2. Which category of biological molecules is found in the highest concentration in the human
body based on percent of body weight?**
A) Nucleic acids
B) Lipids
C) Carbohydrates
*D) Proteins*
**Rationale:** Proteins are found in the highest concentration in the body based on percent of
body weight calculations. They are essential for structure, function, and regulation of tissues and
organs. They serve as enzymes, structural components, and signaling molecules .
---
**3. Which of the following is NOT a class of biological macromolecule?**
A) Carbohydrates
B) Lipids
C) Proteins
*D) Minerals*
**Rationale:** The four major classes of biological macromolecules essential for life are
carbohydrates, lipids, proteins, and nucleic acids. Minerals are inorganic elements that are
important for health but are not classified as biological macromolecules .
---
**4. Athletes seeking to increase muscle mass and strength should increase their intake of which
biological molecule?**
,Page 3 of 115
A) Carbohydrates
B) Lipids
*C) Proteins*
D) Nucleic acids
**Rationale:** Proteins are essential for building and repairing muscle tissue. They are polymers
of amino acids and are the primary structural component of muscle. Athletes need adequate
protein to support muscle growth and repair .
---
**5. How are lipids different from other organic molecules?**
A) They are indivisible
*B) They are not water soluble*
C) They contain zinc
D) They form long proteins
**Rationale:** Lipids are hydrophobic, meaning they are not water soluble. This property is due
to their nonpolar nature and is a key characteristic that distinguishes them from other organic
molecules like carbohydrates and proteins .
---
**6. Which of the following is NOT a steroid?**
A) Cholesterol
, Page 4 of 115
B) Estrogen
C) Testosterone
*D) Hemoglobin*
**Rationale:** Hemoglobin is a protein, not a steroid. Cholesterol, estrogen, and testosterone are
all steroids—lipids characterized by a four-ring carbon structure. Hemoglobin is the oxygen-
carrying protein found in red blood cells .
---
**7. What are the two main categories of fatty acids?**
A) Trans fat and saturated fat
B) Trans fat and unsaturated fats
*C) Saturated fats and unsaturated fats*
D) Saturated fats and polyunsaturated fats
**Rationale:** Fatty acids are classified into two main categories: saturated fats (no double
bonds between carbon atoms) and unsaturated fats (contain one or more double bonds). This
classification affects their physical properties and health implications .
---
**8. Beeswax is an example of what kind of molecule?**
A) Carbohydrate
*B) Lipid*
C) Protein
BIOLOGY MCB3023 HESI A2 BIOLOGY RATED
A+
COMPLETE PRACTICE QUESTION BANK
LATEST 2026-2027 ACADEMIC YEAR
ITSJEREGUIDES
# SECTION I: CHEMISTRY OF LIFE & BIOLOGICAL MOLECULES
**1. Why is polarity considered the most important characteristic of water for biological
systems?**
A) The results of polarity are covalent bonding, a low specific heat value, and its versatile
solvent properties
B) The results of polarity are ionic bonding, a high specific heat value, and its versatile solvent
properties
*C) The results of polarity are hydrogen bonding, a high specific heat value, and its versatile
solvent properties*
D) The results of polarity are hydrogen bonding, a low specific heat value, and its versatile
solvent properties
**Rationale:** Water's polarity leads to hydrogen bonding, which gives water a high specific
heat value (allowing it to resist temperature changes) and makes water a versatile solvent. These
properties are essential for biological systems as they enable temperature regulation and serve as
the medium for biochemical reactions .
---
,Page 2 of 115
**2. Which category of biological molecules is found in the highest concentration in the human
body based on percent of body weight?**
A) Nucleic acids
B) Lipids
C) Carbohydrates
*D) Proteins*
**Rationale:** Proteins are found in the highest concentration in the body based on percent of
body weight calculations. They are essential for structure, function, and regulation of tissues and
organs. They serve as enzymes, structural components, and signaling molecules .
---
**3. Which of the following is NOT a class of biological macromolecule?**
A) Carbohydrates
B) Lipids
C) Proteins
*D) Minerals*
**Rationale:** The four major classes of biological macromolecules essential for life are
carbohydrates, lipids, proteins, and nucleic acids. Minerals are inorganic elements that are
important for health but are not classified as biological macromolecules .
---
**4. Athletes seeking to increase muscle mass and strength should increase their intake of which
biological molecule?**
,Page 3 of 115
A) Carbohydrates
B) Lipids
*C) Proteins*
D) Nucleic acids
**Rationale:** Proteins are essential for building and repairing muscle tissue. They are polymers
of amino acids and are the primary structural component of muscle. Athletes need adequate
protein to support muscle growth and repair .
---
**5. How are lipids different from other organic molecules?**
A) They are indivisible
*B) They are not water soluble*
C) They contain zinc
D) They form long proteins
**Rationale:** Lipids are hydrophobic, meaning they are not water soluble. This property is due
to their nonpolar nature and is a key characteristic that distinguishes them from other organic
molecules like carbohydrates and proteins .
---
**6. Which of the following is NOT a steroid?**
A) Cholesterol
, Page 4 of 115
B) Estrogen
C) Testosterone
*D) Hemoglobin*
**Rationale:** Hemoglobin is a protein, not a steroid. Cholesterol, estrogen, and testosterone are
all steroids—lipids characterized by a four-ring carbon structure. Hemoglobin is the oxygen-
carrying protein found in red blood cells .
---
**7. What are the two main categories of fatty acids?**
A) Trans fat and saturated fat
B) Trans fat and unsaturated fats
*C) Saturated fats and unsaturated fats*
D) Saturated fats and polyunsaturated fats
**Rationale:** Fatty acids are classified into two main categories: saturated fats (no double
bonds between carbon atoms) and unsaturated fats (contain one or more double bonds). This
classification affects their physical properties and health implications .
---
**8. Beeswax is an example of what kind of molecule?**
A) Carbohydrate
*B) Lipid*
C) Protein
