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4.2 Infectious Diseases 🦠

infectious diseases

Introduction to infectious diseases

Infectious diseases is an extension JC2 topic in H2 BIOLOGY in A levels. This is a new topic students see in exams for the first time in 2017. It extents upon concepts in J1 of both HIV and influenza virus seen in J1 as well as adding Mycobacterium tuberculosis. The topic investigates how these pathogens can cause disease and how the host immune system responds.

Materials for infectious diseases

Phrasing errors

  • Penicillin inhibits bacterial cell wall.
  • Disseminated tuberculosis is the spread of tubercle to the rest of the body.
  • Semi-synthetic penicillins are completely different from the natural penicillins and are therefore resistant to penicillinase.

Exam tips

  • Antibiotics ≠ antiviral drugs.
  • You can use Tubercles and granulomas interchangeably.
  • When describing the infections of HIV and Influenza virus for the new syllabus, remember to include details of the immune system

BYang’s tough question bank

  • Explain why penicillin, when it was first secreted by the fungus is not universally effective against bacteria. In addition, explain why it may not work against a susceptible bacteria. [4m. Created 201006]
  • Explain why viral antigenic drift is not always productive and why this phenomenon, as well as mutations that reduce immune recognition does not completely prevent the virus from continuing to use the host for its reproductive cycle. In addition, identify and describe a process in the adaptive immune response that corresponds to the viral antigenic drift. [10m. Created 220518]
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