Bacteria population growth lesson plan


Subjects: , , , , , , , ,
Tags: , , ,
Click for resource → URL

This science/math lesson plan is an introduction to exponential growth and reproduction through mitosis. Students start by noticing and wondering based on still frames from a video of bacteria growing. After recognizing that the population is doubling, students work to see how long it will take for 2 bacteria to become one million bacteria through doubling. The math activity is followed by readings on E. coli and antibiotics.

This lesson plan could be used on its own or as part of a unit on genetics or evolution. The full lesson is attached as a pdf. The url above links to a Google Drive folder with the lesson and other materials. Please share comments below if you use the lesson.

Print Friendly, PDF & Email

November 21st, 2016 · · 2 Comments »

2 thoughts on “Bacteria population growth lesson plan”

  1. Eric,

    I read somewhere recently that if bacteria grow exponentially every 20 minutes, as is in the lesson plan, the mass of bacteria after two days of growth would out weigh the earth (given the condition that the bacteria would have something to feed on). I haven’t done the math myself to see if it’s true….

    Another math adventure….

    Patricia

    Reply

  2. I just ran across some great follow-up questions for this lesson.

    From The Parable of the Bacteria in a Bottle, developed by Physics Professor Al Bartlett, U. Colorado

    The Set-up
    11:00
    You place a single bacterium in a nutrient-filled bottle at 11:00 am. It grows and divides into two bacteria at 11:01. These two bacteria each grow and divide into 4 bacteria at 11:02, which grow and divide into 8 bacteria at 11:03, and so on. (i.e., doubling time of 1 minute.)

    12:00
    Bottle is full, nutrients gone, all the bacteria die.

    Questions

    • When was the bottle half-full?
    • You are a mathematically-sophisticated bacterium, and at 11:56 you recognize the impending disaster. You immediately jump on your soapbox and warn that unless your fellow bacteria slow their growth dramatically, the end is just four minutes away. Will anyone believe you?
    • Just before disaster strikes, a bacterial space program discovers three more bottles in the lab. With a population redistribution program, how much time do the 3 new bottles buy the colony?

    http://www.cryerfamily.eclipse.co.uk/BacteriaBottleParable.htm

    Reply

Add Your Comment