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Question #47549
The Question
In a tissue culture experiment, a researcher extracts the endosperm from a mature Pinus seed and subjects it to a culture medium containing a high Cytokinin-to-Auxin ratio to induce rapid cell proliferation. Which of the following correctly describes the ploidy of the resulting callus and its developmental origin?
Options
- A.
Haploid (n); it is a pre-fertilization tissue representing the female gametophyte.
- B.
Triploid (3n); it is formed by triple fusion and the ploidy is maintained during proliferation.
- C.
Diploid (2n); high cytokinin levels induce endoreduplication to sustain rapid mitotic divisions.
- D.
Diploid (2n); the hormonal ratio forces the gametophytic cells to differentiate into a sporophyte.
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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
Gymnosperm Endosperm|Evolution|Plant Kingdom|Life Cycle
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently conflate the term 'endosperm' across all seed plants, defaulting to the angiosperm (3n) model.
Additionally, a common misconception is that hormonally induced hyper-proliferation (rapid mitosis) alters ploidy or forces a transition to the diploid sporophytic state.
The trap tests the synthesis of Plant Kingdom (gymnosperm endosperm origin) and Plant Growth & Development (hormonal tissue culture).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Gymnosperm Endosperm Identity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |