HESI A2 BIOLOGY EXAM ACTUAL –QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
*Core Domains*
*• Cellular Biology*
*• Molecular Genetics*
*• Biochemistry*
*• Metabolic Pathways*
*• Evolution and Natural Selection*
*• Taxonomy and Classification*
*• Plant and Animal Anatomy*
*• Ecology and Ecosystems*
*Introduction*
The HESI A2 Biology Exam Actual is a comprehensive assessment designed to evaluate foundational knowledge
and critical thinking skills in biological sciences. The purpose of this exam is to assess a candidate's readiness for
advanced healthcare education by testing core concepts across molecular, cellular, and organismal biology. The
examination utilizes multiple-choice and scenario-based structures to challenge prospective students on both
theoretical knowledge and practical inquiry. Candidates will encounter problems requiring real-world application,
data interpretation, and clinical-preparatory decision-making, ensuring a robust comprehension of the life sciences
necessary for standard compliance and professional practice.
Section One: Questions 1–100
Question 1
Which of the following organelles is responsible for the synthesis of lipids and the detoxification of drugs within a
,eukaryotic cell?
A. Rough endoplasmic reticulum
B. Golgi apparatus
🟢 C. Smooth endoplasmic reticulum
D. Lysosome
🔴 RATIONALE: The smooth endoplasmic reticulum synthesizes lipids, phospholipids, and steroids. It also plays
a key role in carbohydrate metabolism and the detoxification of drugs and poisons, particularly in liver cells.
Question 2
A researcher isolates a single-celled organism from a hot spring. The organism lacks a membrane-bound nucleus
but contains a cell wall composed of pseudomurein. In which domain should this organism be classified?
A. Bacteria
🟢 B. Archaea
C. Eukarya
D. Protista
🔴 RATIONALE: Archaea are prokaryotic organisms that lack a true nucleus. Unlike Bacteria, their cell walls lack
peptidoglycan and can be composed of pseudomurein, and they are frequently found in extreme environments
like hot springs.
Question 3
During which phase of mitosis do sister chromatids separate and move toward opposite poles of the cell?
A. Prophase
B. Metaphase
,🟢 C. Anaphase
D. Telophase
🔴 RATIONALE: During anaphase, the sister chromatids are pulled apart by the spindle fibers and migrate toward
opposite poles of the dividing cell.
Question 4
Which metabolic pathway occurs entirely within the cytoplasm of both prokaryotic and eukaryotic cells?
🟢 A. Glycolysis
B. Krebs cycle
C. Electron transport chain
D. Oxidative phosphorylation
🔴 RATIONALE: Glycolysis is an anaerobic process that breaks down glucose into pyruvate and occurs entirely
within the cytoplasm of virtually all living cells.
Question 5
A patient presenting with extreme fatigue is found to have a genetic defect that impairs the function of the electron
transport chain. Which cellular currency will this patient's cells struggle to produce in sufficient quantities?
A. NADP+
B. FADH2
🟢 C. ATP
D. Pyruvate
🔴 RATIONALE: The electron transport chain is the primary site for oxidative phosphorylation, which generates
the majority of cellular adenosine triphosphate (ATP) required for energy.
, Question 6
What type of chemical bond is formed between the carboxyl group of one amino acid and the amino group of
another amino acid during translation?
A. Hydrogen bond
B. Ionic bond
🟢 C. Peptide bond
D. Phosphodiester bond
🔴 RATIONALE: A peptide bond is a covalent bond formed via a dehydration reaction linking the carboxyl group
of one amino acid to the amino group of another.
Question 7
In a laboratory setting, a technician accidentally places red blood cells into a hypotonic solution. What is the
expected outcome for these cells?
🟢 A. The cells will swell and undergo lysis.
B. The cells will shrink and crenate.
C. The cells will remain unchanged.
D. The cells will actively pump out water via exocytosis.
🔴 RATIONALE: In a hypotonic solution, water moves down its concentration gradient into the cells, causing them
to swell and burst (lysis) due to the lack of a rigid cell wall.
Question 8
Which of the following represents the correct sequence of ecological levels of organization, ranging from the most
specific to the most broad?
RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
*Core Domains*
*• Cellular Biology*
*• Molecular Genetics*
*• Biochemistry*
*• Metabolic Pathways*
*• Evolution and Natural Selection*
*• Taxonomy and Classification*
*• Plant and Animal Anatomy*
*• Ecology and Ecosystems*
*Introduction*
The HESI A2 Biology Exam Actual is a comprehensive assessment designed to evaluate foundational knowledge
and critical thinking skills in biological sciences. The purpose of this exam is to assess a candidate's readiness for
advanced healthcare education by testing core concepts across molecular, cellular, and organismal biology. The
examination utilizes multiple-choice and scenario-based structures to challenge prospective students on both
theoretical knowledge and practical inquiry. Candidates will encounter problems requiring real-world application,
data interpretation, and clinical-preparatory decision-making, ensuring a robust comprehension of the life sciences
necessary for standard compliance and professional practice.
Section One: Questions 1–100
Question 1
Which of the following organelles is responsible for the synthesis of lipids and the detoxification of drugs within a
,eukaryotic cell?
A. Rough endoplasmic reticulum
B. Golgi apparatus
🟢 C. Smooth endoplasmic reticulum
D. Lysosome
🔴 RATIONALE: The smooth endoplasmic reticulum synthesizes lipids, phospholipids, and steroids. It also plays
a key role in carbohydrate metabolism and the detoxification of drugs and poisons, particularly in liver cells.
Question 2
A researcher isolates a single-celled organism from a hot spring. The organism lacks a membrane-bound nucleus
but contains a cell wall composed of pseudomurein. In which domain should this organism be classified?
A. Bacteria
🟢 B. Archaea
C. Eukarya
D. Protista
🔴 RATIONALE: Archaea are prokaryotic organisms that lack a true nucleus. Unlike Bacteria, their cell walls lack
peptidoglycan and can be composed of pseudomurein, and they are frequently found in extreme environments
like hot springs.
Question 3
During which phase of mitosis do sister chromatids separate and move toward opposite poles of the cell?
A. Prophase
B. Metaphase
,🟢 C. Anaphase
D. Telophase
🔴 RATIONALE: During anaphase, the sister chromatids are pulled apart by the spindle fibers and migrate toward
opposite poles of the dividing cell.
Question 4
Which metabolic pathway occurs entirely within the cytoplasm of both prokaryotic and eukaryotic cells?
🟢 A. Glycolysis
B. Krebs cycle
C. Electron transport chain
D. Oxidative phosphorylation
🔴 RATIONALE: Glycolysis is an anaerobic process that breaks down glucose into pyruvate and occurs entirely
within the cytoplasm of virtually all living cells.
Question 5
A patient presenting with extreme fatigue is found to have a genetic defect that impairs the function of the electron
transport chain. Which cellular currency will this patient's cells struggle to produce in sufficient quantities?
A. NADP+
B. FADH2
🟢 C. ATP
D. Pyruvate
🔴 RATIONALE: The electron transport chain is the primary site for oxidative phosphorylation, which generates
the majority of cellular adenosine triphosphate (ATP) required for energy.
, Question 6
What type of chemical bond is formed between the carboxyl group of one amino acid and the amino group of
another amino acid during translation?
A. Hydrogen bond
B. Ionic bond
🟢 C. Peptide bond
D. Phosphodiester bond
🔴 RATIONALE: A peptide bond is a covalent bond formed via a dehydration reaction linking the carboxyl group
of one amino acid to the amino group of another.
Question 7
In a laboratory setting, a technician accidentally places red blood cells into a hypotonic solution. What is the
expected outcome for these cells?
🟢 A. The cells will swell and undergo lysis.
B. The cells will shrink and crenate.
C. The cells will remain unchanged.
D. The cells will actively pump out water via exocytosis.
🔴 RATIONALE: In a hypotonic solution, water moves down its concentration gradient into the cells, causing them
to swell and burst (lysis) due to the lack of a rigid cell wall.
Question 8
Which of the following represents the correct sequence of ecological levels of organization, ranging from the most
specific to the most broad?
