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Question #45501
The Question
A targeted genetic mutation in a typical angiosperm completely suppresses the formation of the filiform apparatus in the embryo sac, while all other structures, including the pollen grains, remain viable. Which of the following statements correctly describes the most direct physiological consequence of this mutation following pollination?
Options
- A.
Pollen-pistil interaction on the stigma will fail due to the absence of chemical dialogue, preventing pollen germination.
- B.
The pollen tube will enter through the chalazal end (chalazogamy) and directly release male gametes into the central cell, forming only the endosperm.
- C.
Chemotropic guidance into the synergid will fail, preventing male gamete release and resulting in the absolute failure of both syngamy and triple fusion.
- D.
The pollen tube will enter the synergid normally but fail to rupture, leading to the degeneration of both the egg cell and the secondary nucleus.
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
Synergid Filiform Apparatus|Pollen Tube|Chemotaxis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot & Location Trap: Students frequently conflate the two distinct 'chemical dialogues' in plant reproduction.
The first occurs on the stigma (pollen-pistil interaction for compatibility/germination), while the second occurs deep within the ovule (filiform apparatus guiding the tube into the synergid).
This question tests the precise anatomical location and functional sequence of these events, while also debunking the misconception that chalazogamy bypasses the need for synergids.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Sexual Reproduction in Flowering Plants - Class 12 |
| Concept | Synergid Filiform Apparatus |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |