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Question #45265
The Question
During an advanced ICSI (Intracytoplasmic Sperm Injection) procedure, a reproductive endocrinologist extracts round spermatids from a patient suffering from a spermiogenesis arrest and injects one directly into a mature secondary oocyte. Although syngamy (fusion of pronuclei) is successful, the embryo fails to develop further. Which of the following best explains the physiological basis for this developmental arrest?
Options
- A.
The secondary oocyte fails to complete Meiosis II because the spermatid lacks an acrosome to dissolve the zona pellucida.
- B.
The zygote fails to undergo its first cleavage due to the absence of a mature paternally-contributed proximal centriole.
- C.
The male and female pronuclei fail to fuse because the round spermatid is still a diploid cell.
- D.
The zygote undergoes immediate apoptosis due to the absence of paternally-contributed mitochondria for early cleavage energy.
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
Centriole Duplication Timing|Spermiogenesis vs. Spermiation|ICSI Procedure
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'spermatids are haploid' and assume that simply injecting a haploid nucleus is sufficient for embryogenesis.
This question tests the NCERT-Plus application of sperm structural anatomy (specifically the centrioles in the neck region formed during spermiogenesis) and connects it to the functional requirement of the proximal centriole for the zygote's first mitotic cleavage.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell Cycle and Cell Division - Class 11 |
| Concept | Centriole Duplication Timing |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |