Infectious Disease: Evolving Challenges to Human Health
BAM! Microbe Multiplication Magic
 Overview of Activity
By following a simple formula modeling the replication of bacteria, students will determine how long it takes a bacteria population to grow in different environments. They will then plot graphs to shows their findings.
Activity Type: In Class Mathematical Skills and Graphing Activity
URLs: http://www.bam.gov/teachers/epidemiology_microbe_magic.html
Grade Level: 6-8
Level of Difficulty: Intermediate and Advanced
Amount of Time Required for Activity: One 40-minute Class Period
Recommended Uses:
Prior to attending the exhibit, this activity may be used to engage students in thinking about microbial evolution and how environment affects population size
.
After visiting the exhibit, it may be used to reinforce and highlight microbial colony growth under different conditions, including the occurrence of microbial evolution.
Description
In this in class activity, students will be looking at the rapidity of bacterial colony growth. They will be given a data table showing four hours of incubation time for a bacterial colony. They will need to calculate on their own the number of bacterial colonies present over 15-minute intervals given a starting count of two bacterial colonies under ideal conditions. They will then plot their results as a line graph and discuss that in their groups. Following this portion of the activity, students will then discuss the conditions (e.g. temperature) that influence bacterial colony growth. They then repeat this procedure over the same amount of time, but model the results of bacterial colonies growing in less than ideal conditions and compare the results of both of their final graphs.
This activity was designed by the Centers for Disease Control and Prevention (CDC).
Relation to the Science Standards
Middle School
Content Standard A - Understandings About Scienctific Inquiry
Content Standard C - Reproduction and Heredity
Content Standard C - Populations and Ecosystems
Content Standard C - Diversity and Adaptations of Organisms
Related Part of the Exhibit
Microbial Evolution
Additional Related Links
http://www.bam.gov/teachers/activities/epi_4_microbe_magic.pdf
http://www.cellsalive.com/ecoli.htm
http://mathforum.org/library/drmath/view/58230.html
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