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Question #47545
The Question
While analyzing the seeds of Pinus and Castor, a student notes a fundamental difference in the ploidy and origin of their nutritive tissues. If a hypothetical mutation caused the nutritive tissue of Pinus to exhibit a triploid (3n) state similar to Castor, which of the following statements best explains the normal state of the Pinus endosperm and the developmental implication of this mutation?
Options
- A.
Normally, it is a pre-fertilization female gametophyte (n); a 3n state would necessitate a shift to post-fertilization development via an event like triple fusion, fundamentally altering its independent gametophytic origin.
- B.
Normally, it develops from the diploid nucellus (2n) before fertilization; a 3n state would imply a failure of meiosis during megasporogenesis combined with a single fertilization event.
- C.
Normally, it is a post-fertilization product of the haploid megaspore (n); a 3n state would require the simultaneous fusion of two male gametes with a single haploid egg cell.
- D.
Normally, it is formed by the fusion of a male gamete with a single haploid polar nucleus (n); a 3n state would require the involvement of a diploid central cell prior to fertilization.
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
Prothallus|Generative_Cell_Division|Mitosis_vs_Meiosis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'Endosperm = 3n' from the Sexual Reproduction in Flowering Plants chapter and incorrectly apply it to Gymnosperms.
The trap lies in failing to distinguish the timing (pre-fertilization vs. post-fertilization) and the origin (megaspore mitosis vs. triple fusion) of the nutritive tissue across different plant groups.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Pteridophyte Prothallus Nature |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |