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Quiz Chapter 7: Cellular Respiration

10 questions ยท Form 4 Biology Bab 6: Cellular Respiration

Question 1 of 10Score: 0

During deep, rapid breathing immediately following a 100-meter sprint, an athlete is:

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Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.

1. During deep, rapid breathing immediately following a 100-meter sprint, an athlete is:

  1. A. Inhaling extra carbon dioxide.
  2. B. Paying off an oxygen debt.
  3. C. Undergoing alcohol fermentation.
  4. D. Decreasing metabolic rate.
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Answer: B

Post-exercise hyperventilation increases oxygen intake to break down accumulated lactic acid and restore oxygen debt.

2. How many ATP molecules are produced per glucose molecule during fermentation?

  1. A. 2 ATP
  2. B. 12 ATP
  3. C. 32 ATP
  4. D. 38 ATP
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Answer: A

Because glucose is only partially broken down in fermentation, only 2 ATP molecules are produced during the glycolysis step.

3. Which of the following equations accurately summarizes lactic acid fermentation in human muscle cells?

  1. A. Glucose -> Ethanol + CO2 + 2 ATP
  2. B. Glucose -> Lactic Acid + 2 ATP
  3. C. Glucose + Oxygen -> CO2 + H2O + 38 ATP
  4. D. Pyruvate + Oxygen -> Lactic Acid + CO2
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Answer: B

Lactic acid fermentation converts glucose directly into 2 molecules of lactic acid and a net total of 2 ATP.

4. What is the term given to the condition where oxygen intake is insufficient to meet energy demands during intense exercise, forcing muscles to ferment glucose?

  1. A. Oxygen toxicity
  2. B. Oxygen debt
  3. C. Aerobic capacity
  4. D. Respiratory quotient
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Answer: B

Oxygen debt is the extra amount of oxygen required after strenuous exercise to oxidize accumulated lactic acid in the body.

5. Where is the majority of accumulated lactic acid oxidized into carbon dioxide and water during recovery after strenuous exercise?

  1. A. Kidney
  2. B. Liver
  3. C. Lungs
  4. D. Pancreas
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Answer: B

Lactic acid is transported via blood from muscles to the liver, where about 16 is oxidized to CO2 and water, and 56 is reconverted to glucose/glycogen.

6. Why do human skeletal muscle cells experience fatigue and muscle cramps during strenuous physical activity?

  1. A. Excess oxygen builds up in muscle fibers.
  2. B. Rapid accumulation of lactic acid from anaerobic respiration.
  3. C. Depletion of ethanol in the cytoplasm.
  4. D. Overproduction of carbon dioxide gas inside mitochondria.
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Answer: B

Under oxygen deficit, muscle cells perform lactic acid fermentation; accumulated lactic acid lowers pH and causes muscle cramps and fatigue.

7. Which set of end products is produced during alcohol fermentation in yeast cells?

  1. A. Lactic acid + 2 ATP
  2. B. Ethanol + Carbon dioxide + 2 ATP
  3. C. Carbon dioxide + Water + 38 ATP
  4. D. Pyruvate + Oxygen + 2 ATP
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Answer: B

Yeast decomposes glucose incompletely into ethanol, carbon dioxide, and 2 ATP molecules during alcohol fermentation.

8. During bread making, what causes dough to rise and expand before baking?

  1. A. Ethanol evaporation
  2. B. Carbon dioxide bubbles released during yeast alcohol fermentation
  3. C. Lactic acid accumulation
  4. D. Absorption of atmospheric oxygen
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Answer: B

Carbon dioxide gas produced by yeast during alcohol fermentation gets trapped inside the dough, causing it to swell and rise.

9. Why is energy release in fermentation much lower than in aerobic respiration?

  1. A. Glucose is only partially oxidized, leaving energy stored in end products like ethanol or lactic acid.
  2. B. Enzymes in cytoplasm destroy ATP.
  3. C. Fermentation requires extra ATP input.
  4. D. Carbon dioxide absorbs the chemical energy.
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Answer: A

In fermentation, glucose is incompletely broken down, so most of its chemical energy remains locked inside ethanol or lactic acid molecules.

10. What is the primary organic substrate utilized by living cells to initiate cellular respiration?

  1. A. Fatty acids
  2. B. Glucose
  3. C. Amino acids
  4. D. Lactose
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Answer: B

Glucose is the main respiratory substrate derived from carbohydrate breakdown used by cells to yield ATP.

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