The student then examines a "cancer cell" sample with a defective p53 gene. Counts in 250 cells are: interphase 130, prophase 60, metaphase 30, anaphase 12, telophase 18. The same 24-hour total cycle is assumed.
Compared with normal onion cells, what does the cancer sample suggest?
- A
p53 specifically lengthens anaphase
- B
All cells exit the cycle and become quiescent
- C
Fewer cells are dividing because p53 is required for division
- Dcheck_circle
A larger fraction of cells is in mitosis, consistent with loss of cell-cycle checkpoint control
Explanation
In the cancer sample, only 130/250 = 52% are in interphase compared with 70% in normal cells. A larger fraction is in active mitosis, indicating reduced checkpoint regulation and unregulated proliferation typical of p53 mutants.