Two students each estimated the time that cells in a bean root tip spend in mitosis. Both students used a value of 19 hours for the length of one complete cell cycle. The table shows their results.
Table: The number of cells counted by two students, and each student's estimate of the time cells spend in mitosis
| Student | Total number of cells counted | Number of cells in mitosis | Estimated time spent in mitosis / hours |
|---|---|---|---|
| A | 50 | 6 | 2.3 |
| B | 400 | 40 | 1.9 |
Show how student A calculated the estimate of 2.3 hours.
Suggest which student's estimate is more likely to be accurate. Give a reason for your answer.
Both students counted cells from a root tip. Explain why the estimates would be much less useful if the students had counted cells from a part of the root a long way from the tip.
Give one other way the students could improve the reliability of their estimates.
63 exam-style questions on AQA GCSE Biology 1.2 Cell division, covering 1.2.1 Chromosomes, 1.2.2 Mitosis and the cell cycle, and 1.2.3 Stem cells. Each one has a worked solution and a mark scheme showing where the marks go.