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Question #47498

Difficulty: 8/10 | 🟢 Free

The Question

Lichens are highly sensitive biological indicators of sulfur dioxide ( $SO_2$ ) pollution. The collapse of this mutualistic micro-ecosystem in polluted areas is driven by specific physiological disruptions. Which of the following statements regarding this process is NOT correct?

Options

A.
$SO_2$ acts as a direct inhibitor of chlorophyll synthesis and disrupts thylakoid membranes in the phycobiont.
B.
The ultimate death of the mycobiont occurs due to starvation from the loss of carbohydrate supply, collapsing the symbiotic system.
C.
The primary site of $SO_2$ toxicity is the fungal hyphal network, which loses its ability to absorb atmospheric moisture, leading to algal desiccation.
D.
The extreme sensitivity of lichens to $SO_2$ is exacerbated by their lack of a protective cuticle and stomata, allowing unregulated diffusion of the pollutant.

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Regulatory_Failure

Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.

Concepts Behind This Question

Bacteriophage Genetic Material|Lysosomal pH Homeostasis|Bioactive Molecule Origin

Why This Question Is Tricky

Common Mistakes

Conceptual Pivot: Students often misunderstand the exact physiological target of $SO_2$ in lichens.

Because the mycobiont forms the bulk of the lichen thallus (providing structure and moisture absorption), a common misconception is that the pollutant primarily damages the fungal anatomy first, leading to desiccation.

The pivot is recognizing that $SO_2$ is a specific inhibitor of photosynthesis, making the autotrophic phycobiont the primary casualty, which then indirectly kills the fungus via starvation.

Quick Facts About This Question

Question Information

Subject	Biology
Chapter	Biological Classification - Class 11
Concept	Bacteriophage Genetic Material
Difficulty	8
Cognitive Load	5
Target Solve Time	120 sec
Access	Free