A student examines a prepared slide of an onion root tip under 400x magnification. The root tip contains the meristematic zone where cells are actively dividing. The student counts cells in each phase of the cell cycle in five different fields of view, totaling 250 cells. The counts are: interphase 175, prophase 40, metaphase 15, anaphase 8, telophase 12.
What does the percent of cells in interphase tell us?
- A
Interphase is the shortest phase
- B
Interphase cells are the only ones that grow
- C
Most cells are unable to divide
- Dcheck_circle
Interphase occupies the largest fraction of cell-cycle duration
Explanation
In a randomly sampled population of dividing cells, the fraction in any phase is proportional to the time spent in that phase. With 175/250 = 70% in interphase, this phase dominates the cycle's duration.