WJEC GCSE Biology: Micro-organisms and disease (Unit 2) overview

This module covers the smallest living things, how we use them, and how the body deals with those that cause disease. It draws together two sections of WJEC Biology Unit 2: section 2.7 Micro-organisms and their applications and section 2.8 Disease, defence and treatment. This page maps the module and links to a focused answer page for each topic.

The micro-organisms and disease content

Culturing micro-organisms and their applications

The groups of micro-organisms and bacterial structure, binary fission and growth, aseptic technique, and uses in food, fermentation and biotechnology. See Culturing micro-organisms and their applications.

Pathogens and disease

The causes of disease, the types of pathogen with examples, how pathogens spread, ways to reduce the spread, and non-communicable disease. See Pathogens and disease.

Defence and the immune system

The body's non-specific defences, phagocytes and lymphocytes, antibodies, antigens and antitoxins, and active and passive immunity. See Defence and the immune system.

Vaccines, antibiotics and monoclonal antibodies

Vaccination and memory cells, antibiotics and resistance, monoclonal antibodies, and testing new medicines. See Vaccines, antibiotics and monoclonal antibodies.

How this module is examined

This content is assessed on Unit 2, a written paper of 1 hour 45 minutes, worth 80 marks and 45% of the qualification, tiered at Foundation and Higher. Expect short answer, structured, data response and extended writing questions, including aseptic technique, bacterial growth calculations and the explanation of antibiotic resistance.

How to study this module

Micro-organisms and disease rewards precise recall and clear cause-and-effect reasoning.

1. Learn bacterial structure and aseptic technique. The parts of a bacterial cell and why each aseptic step is used.
2. Practise growth calculations. Use powers of two for binary fission.
3. Know the pathogen types. Virus, bacterium, fungus and protist, each with an example and a route of spread.
4. Separate the defences. Non-specific defences versus phagocytes versus the antibody response.
5. Explain treatment and resistance. Vaccines and memory cells, antibiotics not working on viruses, resistance by natural selection, and monoclonal antibodies.

For the official specification

WJEC publishes the full specification, past papers and mark schemes at wjec.co.uk. Always revise from the current specification and WJEC's own past papers.