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Question #45487
The Question
In a transgenic angiosperm, a targeted gene knockout results in the complete absence of the filiform apparatus in the embryo sac. If wild-type pollen grains (shed at the 2-celled stage) land on a compatible stigma of this mutant plant, which of the following represents the most accurate physiological consequence?
Options
- A.
The generative cell fails to undergo mitosis to form male gametes due to the absence of chemotropic triggers from the embryo sac.
- B.
The pollen tube enters the embryo sac but discharges the male gametes directly into the central cell, resulting in endosperm formation without syngamy.
- C.
The generative cell divides normally during stylar transit, but the pollen tube fails to enter the synergid to discharge the gametes, preventing double fertilization.
- D.
The pollen tube is completely unable to germinate on the stigma because the filiform apparatus is required for initial pollen-pistil recognition.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Synergid_Filiform_Apparatus|Generative_Cell|Male_Gametes
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Isolating the spatial and temporal independence of generative cell division (occurring in the style) from pollen tube guidance and discharge (mediated by the filiform apparatus in the ovule).
Common Misconception: Students often conflate the failure of fertilization with a failure in gamete formation, assuming the embryo sac dictates all post-pollination events, including initial pollen germination and generative cell mitosis.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Sexual Reproduction in Flowering Plants - Class 12 |
| Concept | Generative Cell Division |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |