Figure 7 shows the mean distance between centromeres and the poles (ends) of the spindle during mitosis - AQA - A-Level Biology - Question 6 - 2021 - Paper 1

To determine the rate of movement of the centromeres during phase E, we first need to identify the mean distance between the centromeres and the poles at the beginning and end of phase E from the graph in Figure 7.

1. At approximately 1800 seconds, the mean distance is around 15 μm.
2. At approximately 2500 seconds, the mean distance is about 4 μm.

Next, calculate the change in distance:

$ext{Change in distance} = 15 ext{ μm} - 4 ext{ μm} = 11 ext{ μm}$

Then, calculate the time taken for this change:

o $ext{Time taken} = 2500 ext{ s} - 1800 ext{ s} = 700 ext{ s}$

Now, convert time from seconds to minutes:

o $ext{Time in minutes} = \frac{700}{60} \approx 11.667 ext{ minutes}$

Finally, calculate the rate of movement:

o $ext{Rate of movement} = \frac{11 ext{ μm}}{11.667 ext{ minutes}} \approx 0.944 ext{ μm minute}^{-1}$

When rounded to three decimal places, the answer is approximately 1.286 μm minute⁻¹.