Teacher notes This illustration contains several discussion points relating to the immune response. Pathogens inside the building are holding a couple of white blood cells hostage. Outside, one of the pathogens has been caught (i.e. recognized) by a T-cell, who is co-ordinating the attack (immune response) on the rest of the pathogens. B-cells ( the riot police) are awaiting instructions from the T-cell. The clubs held by the B-cells represent antibodies that they will use to attack the pathogens.
Teacher notes This five-stage animation illustrates the process of phagocytosis of a bacterium by a macrophage. Suitable prompts could include: How does the macrophage know to ingest the bacterium? How does the macrophage envelop the bacterium? How could the macrophage safely destroy the bacterium?
Teacher notes Students could be asked to draw predicted graphs on mini whiteboards and then compare them with these graphs to consolidate their understanding of the previous slide.
Teacher notes This multiple-choice quiz could be used as a plenary activity to assess students’ understanding of infections and immunity. The questions can be skipped through without answering by clicking “next”. Students could be asked to complete the questions in their books and the activity could be concluded by the completion on the IWB.
Immunity to Infection
• Immunity is the acquired ability to defend
against infection by disease-causing
Overview of your immune system
First line of defense: Physical barriers that viruses, bacteria must cross
– skin covers ~2 m2
– Mucous membranes that line digestive, respiratory, reproductive tracts cover
Second line of defense: Innate immune system (germline-encoded
receptors -- no adaptation to specific pathogens)
– Macrophages (Greek for “big eater”), neutrophils, natural killer (NK) cells
Third line of defense (vertebrates only): Adaptive immune system
(adapts to defend against specific pathogens using variable receptors)
– B cells make antibodies that vary -- can make an antibody specific for any
– T cells mediate cellular responses using variable receptors (T cell receptors;