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Question #45255
The Question
A normal human somatic cell has a diploid chromosome number of 2n = 46 and an initial DNA content of 2C in the G1 phase. Which of the following statements regarding the cellular DNA content and chromosome number under specific physiological or experimental arrests is INCORRECT?
Options
- A.
A cell that exits the cell cycle to enter the quiescent G0 phase remains metabolically active with 46 chromosomes and a DNA content of 2C.
- B.
If a cell is blocked by a specific CDK inhibitor immediately prior to the G1/S restriction point, its DNA content will remain 2C.
- C.
Failure of cytokinesis after the completion of telophase results in a polyploid cell containing 46 chromosomes and a DNA content of 4C.
- D.
A cell arrested at the G2/M checkpoint due to radiation-induced DNA damage will possess 46 chromosomes and a DNA content of 4C.
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
Cell Cycle|DNA Replication|G0 Phase
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between DNA content (C) and chromosome number (n) before and after anaphase.
Students often memorize that 'DNA doubles but chromosomes do not' for the S and G2 phases.
The trap lies in applying this rule to a post-telophase cell.
Once anaphase occurs, centromeres split, and the chromosome number temporarily doubles.
A failure in cytokinesis traps these separated chromosomes in one cell, resulting in 92 chromosomes (4n), not 46.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell Cycle and Cell Division - Class 11 |
| Concept | DNA vs Chromosome Content |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |