Global challenges Revision Notes

Communicable Diseases

Communicable diseases, also known as infectious diseases, are caused by microscopic organisms called pathogens (e.g., bacteria, viruses, fungi, protists). These diseases can be spread from one person to another, from animals to humans, or even from the environment. Transmission can occur through direct contact (e.g., touching, kissing), indirect contact (e.g., contaminated surfaces), airborne droplets (e.g., coughing, sneezing), contaminated food or water, or vectors (e.g., insects). Examples include influenza, common cold, measles, malaria, and sexually transmitted infections.

Non-Communicable Diseases (NCDs)

Non-communicable diseases (NCDs), also known as non-infectious or chronic diseases, are conditions that cannot be transmitted between people. They are typically long-lasting and result from a combination of genetic, physiological, environmental, and lifestyle factors. Examples include heart disease, stroke, cancer, diabetes, chronic respiratory diseases, and certain autoimmune conditions. Lifestyle choices such as diet, physical activity, smoking, and alcohol consumption play a significant role in the development and progression of many NCDs.

Key Differences and Examples

The primary distinction lies in transmissibility: communicable diseases *can* be transmitted, while non-communicable diseases *cannot*. Communicable diseases are caused by pathogens, whereas NCDs are often linked to genetics, lifestyle, and environment. For instance, tuberculosis is a communicable disease caused by bacteria, spread through the air. In contrast, Type 2 diabetes is a non-communicable disease influenced by diet, exercise, and genetics, and cannot be caught from another person. Prevention strategies differ greatly, with hygiene and vaccination for communicable, versus lifestyle modification for NCDs.

What Bacteria Spreader Is Used For

Bacteria Spreader is practical apparatus for handling cultures during microbiology practical work. In GCSE or introductory practical science, the annotated diagram helps connect the apparatus to the method, measurement, or observation being tested.

How To Use It In An Exam Answer

Use the marker labels to name the apparatus first, then say why it is suitable. A strong answer links bacteria spreader to handling cultures during microbiology practical work, rather than only saying that it is used in a lab.

Syllabus Link

Primary private mapping: OCR GCSE combined-science-a-gateway J250, Global challenges.

Common Trap

Do not describe apparatus by appearance only. Marks usually come from explaining its function in the practical method.