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Question #47530
The Question
In Citrus, seeds often exhibit polyembryony due to adventive embryony. Suppose a female Citrus plant (2n = 18) is cross-pollinated by a male plant of a compatible related species (2n = 36). Assuming normal double fertilization occurs alongside adventive embryony, what will be the chromosome number and genetic origin of a nucellar embryo and the endosperm within the resulting seed, respectively?
Options
- A.
Nucellar Embryo: 18 (Exclusively maternal); Endosperm: 36 (Biparental)
- B.
Nucellar Embryo: 27 (Biparental); Endosperm: 45 (Biparental)
- C.
Nucellar Embryo: 18 (Exclusively maternal); Endosperm: 27 (Exclusively maternal)
- D.
Nucellar Embryo: 18 (Biparental); Endosperm: 36 (Exclusively maternal)
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
Angiosperm Double Fertilization|Competitive Enzyme Inhibition Kinetics|Androecium Cohesion/Adhesion
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often mistakenly assume that if a seed forms via apomixis (adventive embryony), the entire seed, including the endosperm, is a maternal clone.
This question tests the critical NCERT-Plus nuance that while the nucellar embryo bypasses syngamy (remaining 2n maternal), double fertilization still occurs to form the nutritive endosperm, which receives paternal genes.
The quantitative trap forces students to calculate ploidy via 'n + n + n_male' rather than blindly applying a '3n' formula.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Angiosperm Double Fertilization |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |