Pathogens and Transmission (Joshua Junkermeier)

Hook Videos:

NGSS Standards

Scientific Problems

1. How can we protect population from "germs" or pathogens?

2. What variables impact the size of our population?

3. Is there an "arms-race" between humans and pathogens?

4. How can we improve the designs of hygiene equipment to

reduce the transmission of pathogens?

Activity 1: cleaning produce

  1. Students attempt to clean a potato.

  2. .

  1. Background: the potato is "dusted" with a UV-reactive powder that may or may not be removed from cleaning. The powder simulates a pathogen present on the food (food-borne illness).

  2. Students take their food-potato and examine their effectiven

  1. ess to remove pathogens from their food using a UV-flashlight.Equipment List: potatoes, "UV powder", and available sinks for washing.

Activity 2: Washing Hands to reduce transmission of Pathogens

  1. Participants apply a "clear", UV-reactant paint to their hands.

  2. UV-reactant paint simulates pathogens

  3. Participants proceed to wash their hands as they usually do.

  4. Following their hand rinse, students use the UV-flashlight to determine how effectively they washed their hands.

  5. Followup Video: "best methods for hand washing"

Extensions 1: engineering an effective "air dryer"

  1. Students can develop a design for minimizing the dispersion of pathogens.

  2. Students can run tests with UV-paints (simulation of pathogens) to collect data on dispersion of pathogens.

  3. Incubate cultures from swabbed hand samples.

Extensions 2: transmission of pathogens in the classroom

  1. Video Link: classroom activity

  2. Student volunteer(secretly) to act as a vector for pathogen transfer.

  3. UV-flashlight can track their surface contacts and "infections" during a class period.

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Principles Illustrated:

  • Organisms interact within an ecosystem

  • Pathogen populations may increase when a vector population has a high-density distribution (density dependent variables).

  • Pathogens (bacteria, fungus, and virus) may experience natural selection as a response from human hygiene products and equipment.

  • Products can be improved in order to solve problems.

  • Organisms within a rapidly changing environment (pathogens) are likely to exhibit high reproductive rates as an adaptation for survival.

  • Bacteria may exhibit high mutation rates as an adaptation to selective pressures in the environment (hygiene products)

Prior Knowledge & Experience

  • This lesson may function as a "hook" into population ecology and density-dependent variables.

  • This lesson may function as an exploration with a cell biology unit. Students can investigate the relevance of cell-scale organisms sharing their habitat or community.

  • Students don't require prior knowledge to engage in the content or perform inquiry of the lesson.

Common Misconceptions:

  • Students may not know how effectively the wash their hands.

  • Students may not understand how effective the hygiene equipment and products are in restrooms.

  • Students may not understand the challenges of reducing food-borne illness and cross-contamination due to pathogens from hands and produce.