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Question #45199
The Question
A demographic study of a specific mammalian population reveals an urn-shaped age pyramid. Based on the principles of population ecology, which of the following statements regarding this population is INCORRECT?
Options
- A.
The number of individuals in the pre-reproductive cohort is strictly less than the number of individuals in the reproductive cohort.
- B.
The population is exhibiting a negative growth rate, which mathematically corresponds to an intrinsic rate of natural increase (r) that is less than zero.
- C.
Due to the large size of the reproductive cohort, the population retains positive demographic momentum, ensuring a temporary increase in population size before an eventual decline.
- D.
The population's birth rate (b) has fallen below its death rate (d), indicating that replacement-level fertility is not being achieved.
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
Biotic Potential|Ecosystem Stability|Extinction
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the mere presence of a large reproductive cohort with 'positive demographic momentum'.
However, momentum relies on a massive pre-reproductive base entering the reproductive phase.
In an urn-shaped pyramid, the pre-reproductive base is already diminished, meaning the momentum is exhausted and the population is in immediate decline.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Organisms and Populations - Class 12 |
| Concept | Population Growth Model Dynamics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |