Type 1 diabetes is a chronic condition that arises from a malfunction of the immune system. Which of the following statements correctly explains the immunological basis of this autoimmune disease?
An inherited mutation prevents helper T-lymphocytes from undergoing clonal expansion, leading to a general failure to produce antibodies against bacterial pathogens.
Autoantibodies bind to and block insulin receptors on target cells, preventing glucose uptake and leading to the chronic destruction of muscle and liver tissues.
Self-antigens on the surface of pancreatic β\betaβ-cells are mistakenly recognized as foreign, triggering an immune response that leads to the destruction of these insulin-producing cells.
A viral infection downregulates the expression of major histocompatibility complex (MHC) molecules on pancreatic cells, preventing them from secreting insulin.
40 exam-style questions on OCR A A Level Biology Communicable diseases, disease prevention and the immune system. Each one has a worked solution and a mark scheme showing where the marks go.