4.2 Non-communicable diseases

Unit Summary

This unit is aligned with the AQA GCSE Trilogy specification (4.2 Organisation) and is designed for flexible delivery within a coherent, knowledge-rich curriculum. It builds on prior learning about cells, tissues and organ systems, particularly the cardiovascular and respiratory systems, while continuing to develop students’ working scientifically skills.

The focus of this unit is non-communicable diseases, which are not caused by pathogens and cannot be passed from person to person. Students examine how genetic, lifestyle and environmental risk factors contribute to long-term disease and disrupt normal physiological processes.

Cancer is studied as a disease of uncontrolled cell division. Students revisit the cell cycle and mitosis to understand how mutations in genes controlling cell growth can lead to tumour formation. The differences between benign and malignant tumours are explored, along with how cancer can spread through the body. Links between cancer and risk factors such as smoking, alcohol, obesity and radiation exposure are evaluated using epidemiological evidence.

Coronary heart disease is examined as a disorder of the cardiovascular system caused by fatty deposits in the coronary arteries. Students analyse how risk factors such as high cholesterol, smoking, inactivity and obesity increase the likelihood of heart attack. Treatments, including lifestyle changes and medical interventions, are considered to show how biological understanding informs healthcare.

The effects of smoking and alcohol are explored in detail as major modifiable risk factors. Students study how smoking damages lung tissue and the circulatory system, and how alcohol affects the liver, brain and cardiovascular health. Emphasis is placed on understanding biological mechanisms rather than memorising outcomes alone.

Working scientifically is embedded throughout the unit. Students interpret data on disease incidence, distinguish between correlation and causation, evaluate the reliability of health claims, and analyse trends in public health data.

By linking cellular biology and organ systems to real-world health challenges, this unit develops secure subject knowledge while equipping students to think critically about lifestyle choices and their long-term impact on health.