unit 4 aos 1

• what is an antigen?

  a molecule that induces an immune response
• what is an antibody?

  a protein produced in the body as a specific response to a particular pathogen/allergen
• what are self-cells?


  Cells on your body. These contain self-markers, of which the immune system tolerates. This includes MHC markers)
• What are non-self cells?

  any other type of cell, including antigens
• Explain how prion's are a pathogen

  Prion's are non-cellular pathogens, that are caused by the misfolding of proteins. This can cause mad cow disease
• Explain how virus' are a pathogen


  Virus' are non-cellular pathogens that reproduce by invading a host cell. This includes HIV
• Explain how bacteria are a pathogen

  Bacteria are cellular pathogens that release toxins around cells. This includes tetanus
• Explain how protozoan are a pathogen

  Protozoan are cellular pathogens that feed on the host cell, and reproduce via binary fission. This includes malaria
• Explain how fungi are a pathogen

  Fungi release their spores into the environment to grow. This includes athletes foot
• What are the first line of defense barriers for animals?

  Physical - intact skin, mucous secretion

  Chemical - acidic sweat, stomach acid, lysosome enzyme in tears

  Microbiological - gut microbiome
• What are the first line of defense barriers for plants?

  Physical - bark, waxy cuticle on leaves

  Chemical - citrus produces citronella oil (prevents fungi/bacterial growth), mint produces peppermint which has antibacterial qualities
• What is the innate immune response (second line of defense)?

  all non-specific, non-cellular and molecular responses to pathogens that have breached the first line of defense