Topic 2 – Cells and control

Topic 2 – Cells and control in Edexcel GCSE Biology explores how cells divide, grow, and specialise, and how the body controls these processes. You'll learn about the cell cycle, mitosis, and the importance of stem cells in growth and repair. This topic also covers the nervous system, including the brain and the eye, and how hormones control key functions like the menstrual cycle and blood glucose levels. Understanding these mechanisms is essential for grasping how organisms develop, maintain themselves, and respond to their environment.

This topic builds on your knowledge of cell structure from Topic 1 and connects to later topics like genetics and health. For example, mistakes in cell division can lead to cancer, and understanding the nervous system helps explain reflexes and drug actions. Mastery of this topic is crucial for exam success, as it appears in both Paper 1 and Paper 2, and forms the basis for many applied questions about medical treatments and diseases.

By the end of this topic, you should be able to describe the stages of mitosis, explain how stem cells can be used in medicine, and outline the roles of the brain, eye, and hormones in coordination. You'll also need to interpret diagrams of the cell cycle and nervous pathways, and evaluate the ethical issues surrounding stem cell research. This topic is not just about memorising facts—it's about understanding how living systems are controlled and regulated.