Final answer:
Anaphase represents 3% of the cell cycle in the student's observation. Since the cell cycle is 16 hours, anaphase duration is calculated to be 28.8 minutes based on the calculation method provided. This answer is not matching with the given multiple choice answers, suggesting a potential discrepancy in the question or a need for more specific data.
Step-by-step explanation:
The student observed 200 cells and found that only six were in anaphase. Given that one cell cycle of onion root tissue takes 16 hours, we can calculate the percentage of the cell cycle that anaphase occupies and subsequently determine the time spent in anaphase in minutes. Since 6 out of 200 cells are in anaphase, anaphase represents 3% of the cell cycle (6/200 x 100).
A 16-hour cell cycle is equivalent to 960 minutes (16 x 60). Therefore, to find the duration of anaphase in minutes, we multiply the total time of the cell cycle in minutes by the percentage of time anaphase takes, which gives us:
0.03 (anaphase percent) x 960 minutes (total cell cycle) = 28.8 minutes. Since a single cell cycle takes 16 hours (960 minutes) and the mitotic phase in general takes between 1 and 2 hours, anaphase as one of the stages of mitosis, occupies a relatively short amount of time compared to the total cycle.
If we divide the 28.8 minutes equally among the four stages of mitosis (prophase, metaphase, anaphase, and telophase), each stage would theoretically take 7.2 minutes (28.8 minutes / 4). However, not all stages are of equal length.
Since anaphase is observed in 3% of the cells, we can estimate that the six cells spend approximately 28.8 minutes in anaphase. This does not match with the multiple-choice options presented, hence, either the observed percentages or the options provided may have an error, or additional information about the relative lengths of the different mitotic stages is necessary to determine the exact time for anaphase.