Cell Division: The Cell Cycle, Mitosis & Cancer

An audio revision episode covering Edexcel GCSE Biology Topic 2.1 — Cell Division. We explore the three stages of the cell cycle, the four stages of mitosis in order, how to calculate the number of cells after repeated divisions, and how uncontrolled cell division leads to cancer — including the key difference between benign and malignant tumours.

Episode Overview

Topic: 2.1 Cell Division | Edexcel GCSE Biology (1BI0)

This episode covers:

What is mitosis? — Definition, diploid daughter cells, and the three reasons the body needs mitosis: growth, repair, and asexual reproduction
The cell cycle — Three stages in order: interphase (DNA replication), mitosis (nuclear division), and cytokinesis (cell splitting)
The four stages of mitosis — Prophase, metaphase, anaphase, and telophase (PMAT), with what happens at each stage
Calculating cell numbers — Using the formula 2ⁿ to find the number of cells after n mitotic divisions
Uncontrolled cell division and cancer — How DNA mutations cause the cell cycle to lose control, forming tumours
Benign vs malignant tumours — Key differences: containment, invasion, and spread via the blood and lymphatic system

Exam Tips Covered

Link mitosis to its purpose: growth, repair, or asexual reproduction — not just "to make more cells"
Mitosis is the nuclear division step only; cytokinesis is the separate step where the cell physically divides
Use PMAT to remember the mitosis stages in order
For cell number calculations, apply the formula 2ⁿ and always show working
In benign vs malignant questions: the key distinction is that benign tumours stay in one place; malignant tumours spread

Sources

Mitosis — Edexcel GCSE Biology Revision Notes — Save My Exams
Uncontrolled Cell Division — Edexcel GCSE Biology Revision Notes — Save My Exams