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Question #47554
The Question
In certain angiosperms exhibiting pseudogamous apomixis, a diploid egg cell develops into an embryo without syngamy. Despite the maternal sporophyte possessing a fully functional vascular connection to the ovule via the funicle, the developing seeds frequently abort. Based on the physiological interactions during seed development, what is the most probable cause for this abortion?
Options
- A.
The absence of syngamy prevents the differentiation of the funicular vascular trace, physically isolating the ovule from maternal nutrients.
- B.
Altered double fertilization dynamics cause a ploidy mismatch in the endosperm, leading to its degeneration and subsequent embryo starvation.
- C.
The apomictic embryo lacks the paternal alleles required to induce phloem unloading from the maternal placenta into the embryo sac.
- D.
The unfertilized diploid egg cell undergoes a delayed spontaneous reduction division during early embryogenesis, resulting in a lethal haploid state.
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
Meristematic Polarity|Vascular Evolution Sequence|Lateral Meristems
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that because apomixis bypasses syngamy (fertilization of the egg), it bypasses double fertilization entirely.
The trap is failing to recognize that the endosperm (often requiring triple fusion) acts as an obligatory physiological bridge between the maternal vascular supply and the embryo.
A ploidy mismatch in the endosperm leads to seed abortion, highlighting that apomictic embryos are not physiologically independent of endosperm dynamics.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Vascular Evolution Sequence |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |