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Question #46242
The Question
In a polyembryonic Citrus seed, multiple embryos initiate development within the embryo sac, but typically only one or a few reach full maturity with well-developed leaf primordia. Which of the following physiological mechanisms best explains the developmental arrest and truncated phyllotaxy of the subordinate embryos?
Options
- A.
The dominant embryo establishes a strong auxin gradient, acting as a primary sink and inducing correlative inhibition of the subordinate embryos.
- B.
Subordinate embryos undergo arrest because they originate from unfertilized haploid synergids, lacking the genetic vigor for leaf expansion.
- C.
The nucellar tissue selectively secretes Abscisic Acid (ABA) into the adventive embryos, permanently suppressing their shoot apical meristems.
- D.
The zygotic embryo monopolizes the endosperm via rapid suspensor elongation, physically crushing the nucellar embryos prior to the globular stage.
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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
Leaf Modifications|Embryogeny Directionality|Polyembryony Mechanisms
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' requires students to synthesize 'Polyembryony' (Class 12 Reproduction) with 'Apical Dominance and Source-Sink Dynamics' (Class 11 Plant Physiology).
A common misconception is treating all embryos in a polyembryonic seed as physiologically isolated, failing to recognize the intra-seed hormonal competition and correlative inhibition that dictates which embryo ultimately survives.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Leaf Modifications |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |