Why Is Listeria So Dangerous?

Why do we refrigerate food? To keep bacteria from ruining the food. Refrigeration slows down bacterial growth, allowing us to keep food in our homes for a longer time. But what happens when bacteria continue to grow even in a refrigerator?

This is one reason why the bacterium known as listeria is so dangerous: It continues to grow even when refrigerated. In this module, we study exponential growth models for bacteria. We look at piecewise functions that show bacterial growth before and after refrigeration. 

Students will explore time-dependent bacterial growth functions. They will analyze data in tables and in graphs. They'll use the Desmos graphing calculator to explore the properties of exponential functions.

Math Concepts

  • Functions
  • Problem Solving
  • Algebra

Learning Objectives

  • Graphing exponential data
  • Graphing exponential functions
  • Developing and analyzing mathematical models

Prerequisite Skills

  • Basic understanding of functions
  • Basic understanding of exponential expressions
Common Core Standards CCSS.MATH.CONTENT.HSF.BF.A.1, CCSS.MATH.CONTENT.HSF.LE.A.1
Lesson Duration 20 mins
Grade Range 8th - 11th Grade

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