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Question #46275
The Question
A mutant strain of Pisum sativum (Family Fabaceae) is discovered to exhibit high frequencies of nucellar polyembryony. Given its standard floral formula (% K(5) C1+2+(2) A(9)+1 G1), which of the following represents the most accurate anatomical and developmental consequence of this mutation?
Options
- A.
The pod develops from a monocarpellary, unilocular ovary, but individual seeds contain multiple embryos, decoupling the total embryo count from the initial ovule count.
- B.
The marginal placentation shifts to axile placentation to support the increased nutritional demand of multiple embryos per seed.
- C.
The gynoecium structure modifies from a monocarpellary to a syncarpous multilocular ovary to physically separate the competing embryos.
- D.
The number of seeds per pod increases drastically because each nucellar embryo develops its own independent integuments and seed coat.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Fabaceae Floral Formula|Polyembryony Mechanisms|Fruit Structure DNA
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between 'ovule/seed count' and 'embryo count'.
Students often confuse polyembryony (multiple embryos inside one seed) with an increase in the total number of seeds or carpels.
The trap tests the strict anatomical boundary of where polyembryony occurs (inside the integuments of an existing ovule) versus macroscopic floral traits (carpel number, placentation) which remain unchanged.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Morphology of Flowering Plants - Class 11 |
| Concept | Fabaceae Floral Formula |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |