Featured in PASCO’s College Biology Instructor Guide

College Biology Instructor Guide


College Instructor edition with 26 experiments covering introductory and general biology topics.

Population Ecology

Lab Summary

Use a colorimeter to explore the effects of habitat size, nutrient availability, initial population density and temperature on the growth rate of E.coli bacteria.



Students use the bacteria E. coli as a model for studying population growth, growth curves, and factors affecting growth.


Students gain experience conducting the following procedures:

  • Comparing the growth rate (r) of E. coli populations in different sized chambers.
  • Comparing r in E. coli populations with different nutrient availability.
  • Comparing r in E. coli populations with different initial population densities.
  • Comparing r in E. coli populations incubated at different temperatures.

Sensors / Equipment Used:

PASPORT Colorimeter Sensor


Our PASPORT Colorimeter records all 4 wavelengths simultaneously--no need to guess at wavelength to get a quality measurement.

Materials Used:

Culture vessels, 15-mL - 3
Culture vessels, 250-mL - 3
Culture vessels, 50-mL - 3
Cuvettes (with colorimeter) - 4
Disposable gloves 
Labeling marker 
Labeling tape 
Lint-free tissue 
Luria-Bertani (LB) broth - 40 mL
Overnight (O/N) culture of E.coli in a 15- mL culture tube - 4 mL
Shaking Incubator (optional) - 1 per class
Squirt bottle with 10% bleach 
Sterile transfer or Pasteur pipets, toothpicks, or inoculating loop
Sterile water - 10 mL

The Associated Bundle:

College Biology Bundle


A complete probeware bundle designed for PASCO's College Biology curriculum

Interface Required

This experiment may require software and an interface for data collection.