There are many types of infectious agents that pose serious health risks to humans. Infectious agents can enter the body through the mouth or nose or even through bites or wounds. From bacteria to fungus to parasites that live off human bodies, understanding how these agents attack our bodies is the first step in developing treatments and cures for the infections they cause. 

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  • Idea for Use in the Classroom:

    Explore the Infectious Agents infographic with students to help them identify and discover how infectious agents invade the body and the types of treatments and preventions available for the illnesses they cause. Allow students to collaborate or work independently.

    Have students make a KWL chart. Ask them to record what they already know about infectious agents in the “K” section of the chart. Next ask students what they want to know and have them fill out their questions in the “W” section. Then introduce the infographic to students and give them time to explore the information.

    Ask students to focus on using the infographic to discover the different ways that infectious agents invade human bodies. Have them find and record specific examples of pathogens that enter the human body through air, water, food, and blood in the “L” chart section, citing specific evidence from the infographic.

    Then have students invent their own pathogen—it must be either a bacterium, protozoa, virus, worm, or fungus. Instruct students to use the information they have learned from the infographic to describe what host their pathogen needs, how their pathogen would infect that host, the symptoms the pathogen would induce in the host, and explain how the infection could be prevented or treated. Tell students to reference the infographic to make sure that their fictional pathogen aligns with the information cited. Encourage students to make a model or a drawing to accompany their written descriptions of their fictional pathogen. Finish by having students present their work to the class.

  • Term Part of Speech Definition Encyclopedic Entry
    bacteria Plural Noun

    (singular: bacterium) single-celled organisms found in every ecosystem on Earth.

    Encyclopedic Entry: Bacteria
    disease Noun

    harmful condition of a body part or organ.

    fungi Plural Noun

    (singular: fungus) organisms that survive by decomposing and absorbing nutrients in organic material such as soil or dead organisms.

    infection Noun

    disease caused by microscopic organisms, such as bacteria.

    parasite Noun

    organism that lives and feeds on another organism.

    protozoa Noun

    one-celled organisms in the kingdom protista, such as amoebas. (singular: protozoan)

    virus Noun

    pathogenic agent that lives and multiplies in a living cell.

    worm Noun

    animal with a long, limbless body.