CAIE A Level Biology 9700 · The mitotic cell cycle
A student prepared a root tip squash from an onion (Allium cepa) and counted the number of cells in each stage of mitosis. The results are shown in the table.
| Stage | Number of cells |
|---|---|
| Prophase | 30 |
| Metaphase | 10 |
| Anaphase | 8 |
| Telophase | 12 |
| Interphase | 450 |
Outline the behaviour of chromosomes and the associated changes to the nuclear envelope, spindle, and cell surface membrane during each of the four stages of mitosis (prophase, metaphase, anaphase, telophase).
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Outline means: Give the main points briefly. Less detail than describe, but every key step has to be there. One short line per step, in order. The marks are for coverage, not depth.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.