WJEC Biology for A2: Student Bk

The cause of disease may be external to the body, e.g. an infection, or internal, e.g. an autoimmune condition. The use of antibiotics is of critical importance in treating bacterial disease. Overuse, especially in farming, has led to the selection of antibiotic-resistant bacteria, making some infections hard to treat. Immunology concerns the immune system and how it protects the body. It studies an organism’s response to invasion by foreign proteins and by microbes and their products. The key organs of the immune system are the bone marrow and the thymus gland. By the end of this topic you will be able to: ▪ Explain that the body is a host to many other organisms. ▪ Describe characteristics and treatment of cholera, tuberculosis, smallpox, influenza and malaria. ▪ Describe the relationship between the pathogenic action of viruses and their mode of reproduction. ▪ Describe the features of antibiotics, including the mechanism of action of penicillin and tetracycline. ▪ Understand how the overuse of antibiotics has resulted in the spread of antibiotic- resistant strains of bacteria. ▪ Understand how natural barriers reduce the risk of infection. ▪ Distinguish the innate from the adaptive immune system. ▪ Describe the primary and secondary immune responses. ▪ Distinguish active from passive immunity. ▪ Describe the differential effectiveness of vaccines. ▪ Consider the ethical and moral implication of vaccination programmes. Topic contents 261 Disease 268 Antibiotics 270 The immune response CH 14 Option A: Immunology and disease 260