OCR GCSE Biology A B6.3 Monitoring and Maintaining Health Exam Questions

About OCR GCSE Biology A B6.3 Monitoring and Maintaining Health

B6.3 is the largest health topic on the OCR Gateway Biology A course, completing Topic B6 Global challenges, assessed in Paper 2 (Foundation) or Paper 4 (Higher). It covers how communicable diseases are caused and spread, how plants and humans defend themselves, and how diseases are prevented and treated with vaccines, antibiotics and new medicines. It also covers non-communicable diseases and lifestyle factors. It links to natural selection and antibiotic resistance in B5.2 and to stem cells in B2.1. Examiners frequently test the immune response, how vaccination works, the stages of drug trials and calculations on bacterial growth or zones of inhibition.

What you need to know

• Pathogens Communicable diseases are caused by pathogens: viruses (for example HIV, tobacco mosaic virus), bacteria (for example tuberculosis), fungi (for example ash dieback) and protists (for example malaria). They spread by air, water, contact, body fluids and vectors.
• Plant defences and diagnosis Plants have physical defences such as cellulose cell walls and waxy cuticles, chemical defences such as antimicrobial substances, and mechanical adaptations. Plant diseases can be identified from symptoms, distribution, laboratory tests and testing kits using antibodies.
• Human defences Non-specific defences include skin, mucus and cilia, stomach acid and platelets for clotting. White blood cells carry out phagocytosis, and lymphocytes produce antibodies and antitoxins specific to an antigen.
• Vaccination A vaccine contains dead, weakened or inactive pathogens or their antigens. Lymphocytes produce antibodies and memory cells, so on reinfection antibodies are made faster and in greater numbers; high vaccination rates give herd immunity.
• Antibiotics and new drugs Antibiotics kill bacteria but not viruses. New medicines go through preclinical testing on cells and animals, then clinical trials on healthy volunteers and patients, often double-blind with a placebo, to test safety, efficacy and dose.
• Non-communicable diseases Cardiovascular disease, many cancers and type 2 diabetes are linked to lifestyle factors such as smoking, diet, alcohol and lack of exercise. Treatments include lifestyle changes, statins, stents and surgery; stem cells and gene technology offer future treatments.

Common mistakes in B6.3 Monitoring and Maintaining Health

• Saying antibiotics can treat viral infections such as flu. Antibiotics only work against bacteria.
• Writing that white blood cells 'eat' or 'kill' pathogens with antibodies in one step. Phagocytes engulf pathogens; lymphocytes produce antibodies that bind to specific antigens.
• Stating that a vaccine contains antibodies. A vaccine contains antigens that stimulate the body to make its own antibodies and memory cells.
• Describing a double-blind trial as one where patients do not know the drug. Neither the patients nor the doctors know who receives the drug or the placebo.
• Forgetting the square in zone of inhibition area. Use area = pi x r^2 with the radius, not the diameter.

Try three B6.3 Monitoring and Maintaining Health exam-style questions