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Question #46832
The Question
During a severe flood, the woody stem of a terrestrial plant is completely submerged. The permanent, non-regulatable pores on the periderm are blocked by water, leading to severe hypoxia in the internal tissues. Which of the following statements is INCORRECT regarding the anatomical and metabolic response of this plant?
Options
- A.
The blocked aerating structures are lenticels, which are formed when the phellogen cuts off parenchymatous complementary cells on the outer side.
- B.
Due to the absence of oxygen as the final hydrogen acceptor, the mitochondrial electron transport chain halts, restricting net ATP synthesis to the cytoplasm.
- C.
To regenerate NAD+ for continued glycolysis, pyruvic acid undergoes a single-step reduction to ethanol catalyzed by alcohol dehydrogenase, without the evolution of CO2.
- D.
Prolonged reliance on this anaerobic pathway leads to cellular toxicity due to ethanol accumulation, while yielding a net gain of only 2 ATP per glucose molecule.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Lenticels|Stomata|Pyruvate_Decarboxylation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the specific enzymatic steps and byproducts of alcoholic versus lactic acid fermentation.
The trap relies on the misconception that plant anaerobic respiration is a direct, single-step reduction lacking CO2 evolution.
It also tests the ability to integrate plant anatomy (secondary growth/lenticels) with cellular respiration (metabolic shifts under hypoxia).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Anatomy of Flowering Plants - Class 11 |
| Concept | Lenticels vs Stomata |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |