ECPI BIO 111 EXAM 2– QUESTIONS AND ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS
RATIONALES | DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
Core Domains
Cell Structure and Function
Biomolecules and Metabolism
Cellular Respiration and Photosynthesis
DNA Structure, Replication, and Gene Expression
Cell Division: Mitosis and Meiosis
Mendelian and Non-Mendelian Genetics
Molecular Biology and Biotechnology
Transport Mechanisms and Cellular Homeostasis
Introduction
This examination assesses the student's mastery of foundational and applied concepts in cellular and molecular
biology. It evaluates knowledge of cell structure, metabolic pathways, genetic inheritance, and the flow of genetic
information. The exam employs multiple-choice and scenario-based questions to test critical thinking, real-world
application, and decision-making skills. Students are expected to demonstrate understanding of regulatory compliance,
,ethical standards in biotechnology, and professional laboratory practices. The assessment is designed to prepare
candidates for advanced coursework and professional certification by emphasizing both theoretical knowledge and its
practical application in scientific and clinical settings.
SECTION ONE: QUESTIONS 1–50
1. Which organelle is primarily responsible for ATP synthesis in eukaryotic cells?
A. Ribosome
B. Mitochondrion
C. Golgi apparatus
D. Lysosome
🟢 Correct Answer: B. Mitochondrion
🔴 Explanation: The mitochondrion is the site of oxidative phosphorylation and the electron transport chain, which
generate the majority of cellular ATP.
2. A cell is placed in a hypertonic solution. What is the expected immediate effect?
A. The cell will swell and burst.
B. The cell will shrivel due to water loss.
,C. The cell will remain unchanged.
D. The cell will actively pump water inward.
🟢 Correct Answer: B. The cell will shrivel due to water loss.
🔴 Explanation: In a hypertonic solution, the solute concentration outside the cell is higher than inside, causing
water to move out via osmosis, leading to cell shriveling.
3. Which of the following best describes the function of the sodium-potassium pump?
A. It moves sodium and potassium down their concentration gradients.
B. It transports three sodium ions out and two potassium ions in, using ATP.
C. It transports two sodium ions out and three potassium ions in, using ATP.
D. It is a passive transport mechanism.
🟢 Correct Answer: B. It transports three sodium ions out and two potassium ions in, using ATP.
🔴 Explanation: The sodium-potassium pump is an active transport mechanism that hydrolyzes ATP to move three
Na+ out and two K+ in, maintaining electrochemical gradients.
4. In a scenario where a patient's cells are unable to perform glycolysis, which process is directly impaired?
, A. The citric acid cycle
B. The breakdown of glucose into pyruvate
C. The electron transport chain
D. The synthesis of fatty acids
🟢 Correct Answer: B. The breakdown of glucose into pyruvate
🔴 Explanation: Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing ATP and NADH.
If glycolysis fails, this initial step of glucose catabolism is blocked.
5. Which of the following is a key difference between DNA and RNA?
A. DNA contains uracil, while RNA contains thymine.
B. DNA is single-stranded, while RNA is double-stranded.
C. DNA contains deoxyribose, while RNA contains ribose.
D. DNA is found only in the nucleus, while RNA is found only in the cytoplasm.
🟢 Correct Answer: C. DNA contains deoxyribose, while RNA contains ribose.
🔴 Explanation: The sugar component of DNA is deoxyribose, which lacks an oxygen atom at the 2' position,
whereas RNA contains ribose.
6. During which phase of mitosis do sister chromatids separate and move to opposite poles?
RATIONALES | DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
Core Domains
Cell Structure and Function
Biomolecules and Metabolism
Cellular Respiration and Photosynthesis
DNA Structure, Replication, and Gene Expression
Cell Division: Mitosis and Meiosis
Mendelian and Non-Mendelian Genetics
Molecular Biology and Biotechnology
Transport Mechanisms and Cellular Homeostasis
Introduction
This examination assesses the student's mastery of foundational and applied concepts in cellular and molecular
biology. It evaluates knowledge of cell structure, metabolic pathways, genetic inheritance, and the flow of genetic
information. The exam employs multiple-choice and scenario-based questions to test critical thinking, real-world
application, and decision-making skills. Students are expected to demonstrate understanding of regulatory compliance,
,ethical standards in biotechnology, and professional laboratory practices. The assessment is designed to prepare
candidates for advanced coursework and professional certification by emphasizing both theoretical knowledge and its
practical application in scientific and clinical settings.
SECTION ONE: QUESTIONS 1–50
1. Which organelle is primarily responsible for ATP synthesis in eukaryotic cells?
A. Ribosome
B. Mitochondrion
C. Golgi apparatus
D. Lysosome
🟢 Correct Answer: B. Mitochondrion
🔴 Explanation: The mitochondrion is the site of oxidative phosphorylation and the electron transport chain, which
generate the majority of cellular ATP.
2. A cell is placed in a hypertonic solution. What is the expected immediate effect?
A. The cell will swell and burst.
B. The cell will shrivel due to water loss.
,C. The cell will remain unchanged.
D. The cell will actively pump water inward.
🟢 Correct Answer: B. The cell will shrivel due to water loss.
🔴 Explanation: In a hypertonic solution, the solute concentration outside the cell is higher than inside, causing
water to move out via osmosis, leading to cell shriveling.
3. Which of the following best describes the function of the sodium-potassium pump?
A. It moves sodium and potassium down their concentration gradients.
B. It transports three sodium ions out and two potassium ions in, using ATP.
C. It transports two sodium ions out and three potassium ions in, using ATP.
D. It is a passive transport mechanism.
🟢 Correct Answer: B. It transports three sodium ions out and two potassium ions in, using ATP.
🔴 Explanation: The sodium-potassium pump is an active transport mechanism that hydrolyzes ATP to move three
Na+ out and two K+ in, maintaining electrochemical gradients.
4. In a scenario where a patient's cells are unable to perform glycolysis, which process is directly impaired?
, A. The citric acid cycle
B. The breakdown of glucose into pyruvate
C. The electron transport chain
D. The synthesis of fatty acids
🟢 Correct Answer: B. The breakdown of glucose into pyruvate
🔴 Explanation: Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing ATP and NADH.
If glycolysis fails, this initial step of glucose catabolism is blocked.
5. Which of the following is a key difference between DNA and RNA?
A. DNA contains uracil, while RNA contains thymine.
B. DNA is single-stranded, while RNA is double-stranded.
C. DNA contains deoxyribose, while RNA contains ribose.
D. DNA is found only in the nucleus, while RNA is found only in the cytoplasm.
🟢 Correct Answer: C. DNA contains deoxyribose, while RNA contains ribose.
🔴 Explanation: The sugar component of DNA is deoxyribose, which lacks an oxygen atom at the 2' position,
whereas RNA contains ribose.
6. During which phase of mitosis do sister chromatids separate and move to opposite poles?
