BIOD-152 Final Exam: Graded Questions with Correct
Answers, Multiple Questions, and Comprehensive
Explanations & Solutions
HIGH-DIFFICULTY, MOST-TESTED BIOD-152 FINAL EXAM QUESTIONS.
These are written to mirror hard instructor-written finals, focusing on scenario analysis, integration,
and “best answer” logic.
BIOD-152 FINAL EXAM
Long-Stem | Toughest & Most-Tested Questions
1. CELL MEMBRANE & OSMOSIS (INTEGRATED SCENARIO)
A red blood cell with an internal solute concentration of 0.9% NaCl is placed into a solution containing
0.3% NaCl. After several minutes, the cell swells and eventually bursts (hemolysis).
Which explanation BEST accounts for this outcome?
A. Sodium ions moved into the cell by active transport
B. Water moved into the cell by osmosis due to a hypotonic environment
C. Water moved out of the cell by facilitated diffusion
D. The membrane became impermeable to solutes
✅ Correct Answer: B
Rationale:
• 0.3% NaCl is hypotonic relative to the cell
• Water moves into the cell via osmosis
• Excess water causes swelling → lysis
2. ENZYMES & METABOLISM (EXAM TRAP)
,A student conducts an experiment measuring enzyme activity at different pH levels. At extremely low
pH, the enzyme stops functioning even though substrate concentration remains constant.
Which explanation BEST explains this observation?
A. Substrate saturation prevents enzyme binding
B. The enzyme’s active site shape has been altered
C. The enzyme becomes a competitive inhibitor
D. ATP is no longer produced
✅ Correct Answer: B
Rationale:
• Extreme pH causes denaturation
• Shape change prevents substrate binding
• Substrate amount is irrelevant if enzyme shape is lost
3. CELLULAR RESPIRATION (PROCESS INTEGRATION)
A muscle cell deprived of oxygen continues to produce ATP for a short period. During this time, lactic
acid accumulates and muscle fatigue occurs.
Which statement BEST explains why ATP production continues briefly?
A. Krebs cycle continues without oxygen
B. Electron transport chain switches to anaerobic mode
C. Glycolysis can function without oxygen
D. Fermentation produces large amounts of ATP
✅ Correct Answer: C
Rationale:
• Glycolysis does not require oxygen
• Fermentation regenerates NAD⁺
• ATP yield is low but sufficient short-term
4. PHOTOSYNTHESIS & ENERGY FLOW
A plant is placed in sunlight but deprived of carbon dioxide. Oxygen production continues, but glucose
synthesis stops.
Which conclusion BEST explains this result?
, A. Light reactions require CO₂
B. Calvin cycle cannot occur without CO₂
C. Oxygen is produced during carbon fixation
D. ATP production requires glucose
✅ Correct Answer: B
Rationale:
• Light reactions → O₂
• Calvin cycle → requires CO₂ to build glucose
• Processes are interdependent but separate
5. MITOSIS vs MEIOSIS (HIGH-YIELD COMPARISON)
A scientist observes a cell undergoing division and notes homologous chromosomes pairing and
exchanging genetic material.
Which conclusion is MOST accurate?
A. The cell is undergoing mitosis
B. The cell is producing genetically identical cells
C. The process increases genetic diversity
D. The daughter cells will be diploid
✅ Correct Answer: C
Rationale:
• Homologous pairing + crossing over = meiosis
• Purpose: genetic variation
• Daughter cells are haploid, not diploid
6. DNA → PROTEIN SYNTHESIS (MULTI-STEP)
A mutation causes a deletion of one nucleotide early in a gene sequence.
Which outcome is MOST likely?
A. One amino acid will change
B. No change in protein structure
C. The entire amino acid sequence downstream will be altered
D. Transcription will stop completely
✅ Correct Answer: C
Answers, Multiple Questions, and Comprehensive
Explanations & Solutions
HIGH-DIFFICULTY, MOST-TESTED BIOD-152 FINAL EXAM QUESTIONS.
These are written to mirror hard instructor-written finals, focusing on scenario analysis, integration,
and “best answer” logic.
BIOD-152 FINAL EXAM
Long-Stem | Toughest & Most-Tested Questions
1. CELL MEMBRANE & OSMOSIS (INTEGRATED SCENARIO)
A red blood cell with an internal solute concentration of 0.9% NaCl is placed into a solution containing
0.3% NaCl. After several minutes, the cell swells and eventually bursts (hemolysis).
Which explanation BEST accounts for this outcome?
A. Sodium ions moved into the cell by active transport
B. Water moved into the cell by osmosis due to a hypotonic environment
C. Water moved out of the cell by facilitated diffusion
D. The membrane became impermeable to solutes
✅ Correct Answer: B
Rationale:
• 0.3% NaCl is hypotonic relative to the cell
• Water moves into the cell via osmosis
• Excess water causes swelling → lysis
2. ENZYMES & METABOLISM (EXAM TRAP)
,A student conducts an experiment measuring enzyme activity at different pH levels. At extremely low
pH, the enzyme stops functioning even though substrate concentration remains constant.
Which explanation BEST explains this observation?
A. Substrate saturation prevents enzyme binding
B. The enzyme’s active site shape has been altered
C. The enzyme becomes a competitive inhibitor
D. ATP is no longer produced
✅ Correct Answer: B
Rationale:
• Extreme pH causes denaturation
• Shape change prevents substrate binding
• Substrate amount is irrelevant if enzyme shape is lost
3. CELLULAR RESPIRATION (PROCESS INTEGRATION)
A muscle cell deprived of oxygen continues to produce ATP for a short period. During this time, lactic
acid accumulates and muscle fatigue occurs.
Which statement BEST explains why ATP production continues briefly?
A. Krebs cycle continues without oxygen
B. Electron transport chain switches to anaerobic mode
C. Glycolysis can function without oxygen
D. Fermentation produces large amounts of ATP
✅ Correct Answer: C
Rationale:
• Glycolysis does not require oxygen
• Fermentation regenerates NAD⁺
• ATP yield is low but sufficient short-term
4. PHOTOSYNTHESIS & ENERGY FLOW
A plant is placed in sunlight but deprived of carbon dioxide. Oxygen production continues, but glucose
synthesis stops.
Which conclusion BEST explains this result?
, A. Light reactions require CO₂
B. Calvin cycle cannot occur without CO₂
C. Oxygen is produced during carbon fixation
D. ATP production requires glucose
✅ Correct Answer: B
Rationale:
• Light reactions → O₂
• Calvin cycle → requires CO₂ to build glucose
• Processes are interdependent but separate
5. MITOSIS vs MEIOSIS (HIGH-YIELD COMPARISON)
A scientist observes a cell undergoing division and notes homologous chromosomes pairing and
exchanging genetic material.
Which conclusion is MOST accurate?
A. The cell is undergoing mitosis
B. The cell is producing genetically identical cells
C. The process increases genetic diversity
D. The daughter cells will be diploid
✅ Correct Answer: C
Rationale:
• Homologous pairing + crossing over = meiosis
• Purpose: genetic variation
• Daughter cells are haploid, not diploid
6. DNA → PROTEIN SYNTHESIS (MULTI-STEP)
A mutation causes a deletion of one nucleotide early in a gene sequence.
Which outcome is MOST likely?
A. One amino acid will change
B. No change in protein structure
C. The entire amino acid sequence downstream will be altered
D. Transcription will stop completely
✅ Correct Answer: C
