Question

A biologist examines a series of cells and counts $160$ cells in interphase, $20$ cells in prophase, $6$ cells in prometaphase, $2$ cells in metaphase, $7$ cells in anaphase, and $5$ cells in telophase. If the complete cell cycle requires $24$ hours, what is the average duration of M phase in these cells ?
Stage Number of cells Proportion of cells Average duration

counted at each stage (hours)
Interphase $1600.809.2$
Prophase $200.102.4$
Prometaphase $60.030.72$
Metaphase $20.010.24$
Anaphase $70.0350.84$
Telophase $50.0250.6$
Totals $2001.024$

• A. 5.6 hr
• B. 19.44 hr
• C. 4.8 hr
• D. 23.6 hr

Answer 1

The correct option is C 4.8 hr

Mitosis consists of 4 phases such as prophase, metaphase, anaphase, and telophase and the phase between 2 mitosis is called as interphase

now as per the questions are given details, on the addition of average duration of all phases of mitosis

2.4+0.72+0.24+0.84+0.6 = 4.8 hr

Thus, the correct answer is option C.