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Comparing Sizes of Microorganisms

Author(s): Nancy Moreno, PhD, Barbara Tharp, MS, Deanne Erdmann, MS, Sonia Rahmati Clayton, PhD, and James P. Denk, MA

Microbial Models

Before students begin to build their scale models, hang the 2.5 m x 2.5 m prepared paper square on the wall or blackboard. Explain that this square represents the size of the period, increased 5,000 times (0.05 mm x 5,000 = 2,500 mm = 2.5 m).

Pass out copies of the Microbe Scaling Chart Student Sheet, and tell students they will be drawing models of various microbes using the same scale (x 5,000) that was used with the period. Reinforce the need for students to make their assigned microbe(s) the correct size and shape, using the pictures and scale model measurements on the Student Sheet as a guide.

Once students have completed their models, you may want to have them place their organism models inside the square. This will give them a better idea of how large the different microbes are, as compared to the size of the period. 

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Funded by the following grant(s)

Science Education Partnership Award, NIH

Science Education Partnership Award, NIH

Grant Number: 5R25RR018605