# A student observes cells from a root tip under a microscope. Most cells are in interphase, but some are in different stages of mitosis. Explain why uncontrolled mitosis in these cells could lead to cancer, and describe what happens during metaphase and anaphase to produce two genetically identical daughter cells.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 2.2 Cell cycle and mitosis · Explain · 5 marks

> Root tip meristem tissue contains actively dividing cells. The cell cycle involves interphase followed by mitosis and cytokinesis.

## Mark scheme (5 marks)

1. Cancer is caused by uncontrolled cell growth and division
2. During metaphase, chromosomes align at the cell equator
3. During anaphase, chromatids are pulled to opposite poles of the cell by spindle fibres
4. Each set of chromatids at the poles contains an identical copy of the genetic information / same number of chromosomes as the parent cell
5. Cytokinesis divides the cytoplasm to produce two genetically identical daughter cells

## Key terms

- [cancer](https://www.gradenine.co.uk/glossary/cancer)
- [metaphase](https://www.gradenine.co.uk/glossary/metaphase)
- [anaphase](https://www.gradenine.co.uk/glossary/anaphase)
- [mitosis](https://www.gradenine.co.uk/glossary/mitosis)

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-observes-cells-from-a-87b19dff) · Published by Druglandscape Ltd.