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Question #46890
The Question
A researcher experimentally maintains elevated titers of Juvenile Hormone (JH) in a female Periplaneta americana during its final (13th) nymphal instar. Which of the following morphological outcomes is most likely to be observed after the subsequent molt?
Options
- A.
Development of a sexually mature adult with a fully formed brood pouch bounded by the 7th, 8th, and 9th sternites.
- B.
Formation of a supernumerary nymph that retains wing pads and fails to develop a distinct genital pouch.
- C.
Accelerated maturation of the ovaries and the premature appearance of anal styles on the 9th sternite.
- D.
Emergence of an adult with functional tegmina but lacking anal cerci on the 10th tergite.
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
Corpora Allata|Cockroach Reproductive Dimorphism|Spermatogenesis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Understanding the specific role of Juvenile Hormone versus Ecdysone.
Students often assume any 'hormone application' accelerates maturation.
This question tests the knowledge that JH is an 'anti-adult' hormone.
It also integrates NCERT anatomical specifics, requiring the student to recall that the brood pouch (7th-9th sternites) and functional wings are exclusive to the adult stage, while wing pads are characteristic of the nymphal stage.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Structural Organisation in Animals - Class 11 |
| Concept | Cockroach Reproductive Dimorphism |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |