Fermentation (Anaerobic) — NEET Biology MCQs with Solutions
Free NEET Biology Fermentation (Anaerobic) MCQs with step-by-step solutions (6 questions). Part of Respiration in Plants. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Fermentation (Anaerobic) · easy · theory
In yeast, anaerobic respiration (fermentation) converts pyruvate to:
A. Water
B. Ethanol and CO₂ ✓ Correct
C. Lactic acid
D. Acetyl CoA
Solution: Yeast performs alcoholic fermentation: pyruvate → acetaldehyde → ethanol + CO₂.
Q2 — Fermentation (Anaerobic) · easy · theory
In our muscle cells during vigorous exercise, pyruvate is converted to ______ under low oxygen:
A. CO₂ and water
B. Glucose
C. Ethanol
D. Lactic acid ✓ Correct
Solution: Lack of O₂ forces lactic acid fermentation in muscles, regenerating NAD⁺ for glycolysis.
Q3 — Fermentation (Anaerobic) · medium · theory
The purpose of fermentation (reducing pyruvate) is to:
A. Fix carbon dioxide
B. Regenerate NAD⁺ so that glycolysis can continue ✓ Correct
C. Produce large amounts of ATP
D. Synthesise glucose
Solution: Fermentation reoxidises NADH back to NAD⁺, allowing glycolysis to keep making its small ATP yield without O₂.
Q4 — Fermentation (Anaerobic) · medium · theory
The net ATP yield per glucose in fermentation is only ______, because:
A. 4 ATP; ETS runs
B. 38 ATP; O₂ is used
C. 2 ATP; glucose is only partially oxidised ✓ Correct
D. 36 ATP; glucose is fully oxidised
Solution: Without the Krebs cycle and ETS, only the 2 ATP of glycolysis are gained — glucose is not fully broken down.
Q5 — Fermentation (Anaerobic) · hard · theory
Both alcoholic and lactic acid fermentation are hazardous because:
A. They produce too much ATP
B. Less than 7% of the energy in glucose is released and not all of it is trapped as ATP ✓ Correct
C. They consume oxygen
D. They release only water
Solution: Fermentation is energetically inefficient (only ~2 ATP) and yields incompletely oxidised, sometimes toxic, products.
Q6 — Fermentation (Anaerobic) · hard · theory
The enzyme pyruvic acid decarboxylase and alcohol dehydrogenase are required in ______ fermentation:
A. Alcoholic (yeast) ✓ Correct
B. Photorespiratory
C. Lactic acid
D. Aerobic
Solution: Alcoholic fermentation needs pyruvate decarboxylase (→ acetaldehyde) and alcohol dehydrogenase (→ ethanol).