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Question #45759
The Question
A population of a stenohaline freshwater teleost is accidentally introduced into an estuarine habitat. Ecologists observe that the population fails to establish, and its growth severely deviates from the expected logistic growth model (dN/dt = rN[(K-N)/K]), ultimately leading to a decline. Which of the following statements correctly integrates the physiological and ecological mechanisms driving this population crash?
Options
- A.
The hyperosmotic environment induces severe exosmosis; the subsequent high ATP expenditure for active ion excretion reduces energy allocation for reproduction, thereby lowering the intrinsic rate of natural increase (r).
- B.
The hypoosmotic environment causes continuous endosmosis, forcing the fish to expend ATP to excrete copious dilute urine, which increases environmental resistance and raises the carrying capacity (K).
- C.
The fluctuating salinity forces the organism to become an osmoconformer, causing the environmental resistance term ((K-N)/K) to approach 1, leading to rapid population expansion.
- D.
The osmotic stress eliminates environmental resistance, shifting the population growth from a logistic (S-shaped) to an exponential (J-shaped) pattern due to competitive release.
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
Stenohaline|Euryhaline|Logistic_Growth
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Organismal Physiology with Population Ecology.
Students often treat the intrinsic rate of natural increase ('r') as a fixed genetic constant, failing to recognize that 'r' is heavily modulated by the metabolic ATP costs of maintaining homeostasis (osmoregulation) under environmental stress.
The trap also tests the directional flow of osmosis (exosmosis vs endosmosis) based on the specific habitat transition.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Osmoregulation in Aquatic Adaptations |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |