Before You Begin
Question #46141
The Question
A researcher is studying a dioecious species of Aschelminthes that exhibits typical NCERT-described sexual dimorphism and follows a human-like XX/XY sex determination system. If complete non-disjunction of the sex chromosomes occurs during Anaphase-I of spermatogenesis in a normal male, which of the following correctly identifies the sex chromosome constitution of the resulting sperms and the expected morphological phenotype of the aneuploid offspring upon fertilization with a normal ovum?
Options
- A.
Sperms: 50% (XY) and 50% (O); Offspring: XXY (shorter phenotype) and XO (longer phenotype)
- B.
Sperms: 50% (XY) and 50% (O); Offspring: XXY (longer phenotype) and XO (shorter phenotype)
- C.
Sperms: 25% (XX), 25% (YY) and 50% (O); Offspring: XXX (longer phenotype) and XYY (shorter phenotype)
- D.
Sperms: 50% (XX) and 50% (YY); Offspring: XXY (shorter phenotype) and XO (longer phenotype)
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
Aschelminthes Sex Differentiation|Down/Klinefelter/Turner Syndrome Karyotypes|Meiotic Reductional Division
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question requires the synthesis of three distinct NCERT concepts: (1) Phylum-specific morphological traits (Aschelminthes females are longer), (2) The precise gametic outcome of Anaphase-I vs Anaphase-II non-disjunction, and (3) Chromosomal sex determination.
The primary trap is confusing Anaphase-I non-disjunction (yielding XY sperms) with Anaphase-II non-disjunction (yielding XX or YY sperms), and failing to map the resulting genetic sex back to the specific morphological dimorphism of the phylum.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Aschelminthes Sex Differentiation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |