HESI A2 VERSION 1 BIOLOGY EXAM
QUESTIONS & ANSWERS (VERIFIED
ANSWERS) WITH EXPERT
EXPLANATIONS | 2026 – 2027 UPDATE
(PDF)
1. Which of the following is the correct hierarchical order of biological classification from the
broadest to the most specific?
A. Kingdom, Class, Phylum, Order, Genus, Family, Species
B. Domain, Kingdom, Order, Class, Family, Genus, Species
C. Species, Genus, Family, Order, Class, Phylum, Kingdom
D. Kingdom, Phylum, Class, Order, Family, Genus, Species
Answer: D
Conceptual Explanation: The standard biological hierarchy follows the order: Kingdom,
Phylum, Class, Order, Family, Genus, and Species.
2. In the scientific method, which step involves a tentative explanation for an observation
that can be tested?
A. Hypothesis
B. Conclusion
,C. Experiment
D. Observation
Answer: A
Conceptual Explanation: A hypothesis is a proposed, testable explanation for a
phenomenon based on observations.
3. What property of water allows it to resist changes in temperature and maintain a stable
environment for aquatic life?
A. Low density as a solid
B. High specific heat
C. High polarity
D. Cohesive behavior
Answer: B
Conceptual Explanation: Water’s high specific heat means it requires a significant amount
of energy to change its temperature, stabilizing surrounding environments.
4. Which type of macromolecule is primarily responsible for long-term energy storage and the
structure of cell membranes?
A. Carbohydrates
B. Lipids
C. Proteins
, D. Nucleic Acids
Answer: B
Conceptual Explanation: Lipids, including fats and phospholipids, serve as long-term
energy storage and form the phospholipid bilayer of membranes.
5. What type of bond links amino acids together to form a protein’s primary structure?
A. Peptide bond
B. Ionic bond
C. Hydrogen bond
D. Phosphodiester bond
Answer: A
Conceptual Explanation: Amino acids are joined by peptide bonds, which are covalent
bonds formed via dehydration synthesis.
6. Which organelle is known as the site of cellular respiration and ATP production?
A. Ribosome
B. Mitochondria
C. Golgi Apparatus
D. Lysosome
Answer: B
QUESTIONS & ANSWERS (VERIFIED
ANSWERS) WITH EXPERT
EXPLANATIONS | 2026 – 2027 UPDATE
(PDF)
1. Which of the following is the correct hierarchical order of biological classification from the
broadest to the most specific?
A. Kingdom, Class, Phylum, Order, Genus, Family, Species
B. Domain, Kingdom, Order, Class, Family, Genus, Species
C. Species, Genus, Family, Order, Class, Phylum, Kingdom
D. Kingdom, Phylum, Class, Order, Family, Genus, Species
Answer: D
Conceptual Explanation: The standard biological hierarchy follows the order: Kingdom,
Phylum, Class, Order, Family, Genus, and Species.
2. In the scientific method, which step involves a tentative explanation for an observation
that can be tested?
A. Hypothesis
B. Conclusion
,C. Experiment
D. Observation
Answer: A
Conceptual Explanation: A hypothesis is a proposed, testable explanation for a
phenomenon based on observations.
3. What property of water allows it to resist changes in temperature and maintain a stable
environment for aquatic life?
A. Low density as a solid
B. High specific heat
C. High polarity
D. Cohesive behavior
Answer: B
Conceptual Explanation: Water’s high specific heat means it requires a significant amount
of energy to change its temperature, stabilizing surrounding environments.
4. Which type of macromolecule is primarily responsible for long-term energy storage and the
structure of cell membranes?
A. Carbohydrates
B. Lipids
C. Proteins
, D. Nucleic Acids
Answer: B
Conceptual Explanation: Lipids, including fats and phospholipids, serve as long-term
energy storage and form the phospholipid bilayer of membranes.
5. What type of bond links amino acids together to form a protein’s primary structure?
A. Peptide bond
B. Ionic bond
C. Hydrogen bond
D. Phosphodiester bond
Answer: A
Conceptual Explanation: Amino acids are joined by peptide bonds, which are covalent
bonds formed via dehydration synthesis.
6. Which organelle is known as the site of cellular respiration and ATP production?
A. Ribosome
B. Mitochondria
C. Golgi Apparatus
D. Lysosome
Answer: B
