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Biology LibreTexts

7: Immune System

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  • By Drs. Jennifer Doherty and. Ingrid Waldron, Department of Biology, University of Pennsylvania, CC-BY-NC 4.0.


    Examines the correlation between the spread of infectious diseases and population growth. 

    • 7.1: Infectious Disease Protocol
      An infectious disease is any disease caused by germs that can be spread from one person to another. Germs include viruses, bacteria, and protozoa. This activity will simulate the spread of an infectious disease. A simulation is a simplified demonstration of a real biological process. Our simulation will show how an infectious disease can spread from one infected person to other people who, in turn, infect others.
    • 7.2: Infectious Disease Teacher's Preparation Notes
      The spread of infectious disease from person to person in a population can result in an exponential increase in the number of infected people. Similarly, when population size doubles repeatedly, this results in exponential growth. The maximum population size that an environment can sustain is called the carrying capacity. As population size approaches the carrying capacity, the rate of growth in population size decreases, resulting in a logistic growth curve.