(a)[5]
Some pathogenic bacteria release toxins that can be chemically modified so that they become harmless. These harmless toxins are known as toxoids. Toxoids are included in vaccines to protect against certain infectious diseases. Describe the response of the immune system to the injection of a toxoid.
(b(i))[3]
Myasthenia gravis (MG) is described as an autoimmune disease. It is a long-term condition that results from a failure of the immune system. Explain why MG is known as an autoimmune disease.
(b(ii))[2]
Suggest why MG is a long-term condition.
(ii)[2]
Suggest why MG is a long-term condition.