1
ECPI BIO 111 EXAM CHAPTERS 8 9 10 11
Actual Exam 2026/2027 Complete Questions and
Verified Answers with Detailed Rationales Pass
Guaranteed - A+ Graded
Section 1: BIO 111 Exam (Chapters 8-11)
Q1: Which of the following is the correct sequence of stages in cellular respiration?
A. Krebs cycle → Glycolysis → Electron transport chain
B. Electron transport chain → Glycolysis → Krebs cycle
C. Glycolysis → Krebs cycle → Electron transport chain [CORRECT]
D. Glycolysis → Electron transport chain → Krebs cycle
Correct Answer: C
Rationale: Cellular respiration begins with glycolysis in the cytoplasm, followed by the Krebs
cycle (citric acid cycle) in the mitochondrial matrix, and concludes with the electron transport
chain on the inner mitochondrial membrane. This sequence ensures glucose is progressively
broken down to maximize ATP production.
Q2: Where does glycolysis occur in the cell?
A. Mitochondrial matrix
B. Cytoplasm [CORRECT]
C. Inner mitochondrial membrane
D. Nucleus
Correct Answer: B
Rationale: Glycolysis is the anaerobic breakdown of glucose into two pyruvate molecules and
occurs in the cytoplasm of all living cells, making it the most ancient and universal energy-
harvesting pathway.
Q3: How many net ATP molecules are produced during glycolysis per glucose molecule?
A. 2 [CORRECT]
B. 4
,2
C. 32
D. 36
Correct Answer: A
Rationale: Glycolysis produces 4 ATP molecules but consumes 2 ATP in the investment phase,
resulting in a net gain of 2 ATP molecules per glucose molecule.
Q4: What is the final electron acceptor in the electron transport chain of cellular respiration?
A. NADH
B. FADH₂
C. Oxygen [CORRECT]
D. Carbon dioxide
Correct Answer: C
Rationale: Oxygen serves as the final electron acceptor in aerobic respiration, combining with
electrons and hydrogen ions to form water. Without oxygen, the electron transport chain cannot
function, and oxidative phosphorylation ceases.
Q5: Which molecule is produced during the Krebs cycle and serves as the primary electron
carrier to the electron transport chain?
A. ATP
B. NADH [CORRECT]
C. Glucose
D. Pyruvate
Correct Answer: B
Rationale: The Krebs cycle generates 3 NADH molecules per acetyl-CoA (6 per glucose), which
carry high-energy electrons to the electron transport chain where they drive ATP synthesis
through oxidative phosphorylation.
Q6: What is the primary purpose of the light-dependent reactions of photosynthesis?
A. To fix carbon dioxide
B. To produce glucose
C. To convert light energy into chemical energy (ATP and NADPH) [CORRECT]
D. To regenerate RuBP
, 3
Correct Answer: C
Rationale: The light-dependent reactions capture photon energy to split water, producing ATP
through photophosphorylation and NADPH, which provide the energy and reducing power
needed for the Calvin cycle.
Q7: In which cellular compartment do the light-independent reactions (Calvin cycle) occur?
A. Thylakoid membrane
B. Thylakoid lumen
C. Stroma [CORRECT]
D. Cytoplasm
Correct Answer: C
Rationale: The Calvin cycle occurs in the stroma of chloroplasts, the fluid-filled space
surrounding the thylakoid membranes, where enzymes use ATP and NADPH from the light
reactions to fix CO₂ into carbohydrates.
Q8: Which pigment is primarily responsible for capturing light energy in photosynthesis?
A. Carotenoids
B. Chlorophyll a [CORRECT]
C. Xanthophyll
D. Anthocyanin
Correct Answer: B
Rationale: Chlorophyll a is the primary photosynthetic pigment that directly participates in the
light reactions by absorbing red and blue light wavelengths and transferring excited electrons to
the electron transport chain.
Q9: What is the source of oxygen released during photosynthesis?
A. Carbon dioxide
B. Glucose
C. Water [CORRECT]
D. Atmospheric oxygen
Correct Answer: C
ECPI BIO 111 EXAM CHAPTERS 8 9 10 11
Actual Exam 2026/2027 Complete Questions and
Verified Answers with Detailed Rationales Pass
Guaranteed - A+ Graded
Section 1: BIO 111 Exam (Chapters 8-11)
Q1: Which of the following is the correct sequence of stages in cellular respiration?
A. Krebs cycle → Glycolysis → Electron transport chain
B. Electron transport chain → Glycolysis → Krebs cycle
C. Glycolysis → Krebs cycle → Electron transport chain [CORRECT]
D. Glycolysis → Electron transport chain → Krebs cycle
Correct Answer: C
Rationale: Cellular respiration begins with glycolysis in the cytoplasm, followed by the Krebs
cycle (citric acid cycle) in the mitochondrial matrix, and concludes with the electron transport
chain on the inner mitochondrial membrane. This sequence ensures glucose is progressively
broken down to maximize ATP production.
Q2: Where does glycolysis occur in the cell?
A. Mitochondrial matrix
B. Cytoplasm [CORRECT]
C. Inner mitochondrial membrane
D. Nucleus
Correct Answer: B
Rationale: Glycolysis is the anaerobic breakdown of glucose into two pyruvate molecules and
occurs in the cytoplasm of all living cells, making it the most ancient and universal energy-
harvesting pathway.
Q3: How many net ATP molecules are produced during glycolysis per glucose molecule?
A. 2 [CORRECT]
B. 4
,2
C. 32
D. 36
Correct Answer: A
Rationale: Glycolysis produces 4 ATP molecules but consumes 2 ATP in the investment phase,
resulting in a net gain of 2 ATP molecules per glucose molecule.
Q4: What is the final electron acceptor in the electron transport chain of cellular respiration?
A. NADH
B. FADH₂
C. Oxygen [CORRECT]
D. Carbon dioxide
Correct Answer: C
Rationale: Oxygen serves as the final electron acceptor in aerobic respiration, combining with
electrons and hydrogen ions to form water. Without oxygen, the electron transport chain cannot
function, and oxidative phosphorylation ceases.
Q5: Which molecule is produced during the Krebs cycle and serves as the primary electron
carrier to the electron transport chain?
A. ATP
B. NADH [CORRECT]
C. Glucose
D. Pyruvate
Correct Answer: B
Rationale: The Krebs cycle generates 3 NADH molecules per acetyl-CoA (6 per glucose), which
carry high-energy electrons to the electron transport chain where they drive ATP synthesis
through oxidative phosphorylation.
Q6: What is the primary purpose of the light-dependent reactions of photosynthesis?
A. To fix carbon dioxide
B. To produce glucose
C. To convert light energy into chemical energy (ATP and NADPH) [CORRECT]
D. To regenerate RuBP
, 3
Correct Answer: C
Rationale: The light-dependent reactions capture photon energy to split water, producing ATP
through photophosphorylation and NADPH, which provide the energy and reducing power
needed for the Calvin cycle.
Q7: In which cellular compartment do the light-independent reactions (Calvin cycle) occur?
A. Thylakoid membrane
B. Thylakoid lumen
C. Stroma [CORRECT]
D. Cytoplasm
Correct Answer: C
Rationale: The Calvin cycle occurs in the stroma of chloroplasts, the fluid-filled space
surrounding the thylakoid membranes, where enzymes use ATP and NADPH from the light
reactions to fix CO₂ into carbohydrates.
Q8: Which pigment is primarily responsible for capturing light energy in photosynthesis?
A. Carotenoids
B. Chlorophyll a [CORRECT]
C. Xanthophyll
D. Anthocyanin
Correct Answer: B
Rationale: Chlorophyll a is the primary photosynthetic pigment that directly participates in the
light reactions by absorbing red and blue light wavelengths and transferring excited electrons to
the electron transport chain.
Q9: What is the source of oxygen released during photosynthesis?
A. Carbon dioxide
B. Glucose
C. Water [CORRECT]
D. Atmospheric oxygen
Correct Answer: C
