Educational Model: Engelmann’s Experiment
The model illustrates the well-known experiment by Theodor Engelmann, conducted in the late 19th century
This model is a component of the IUMC (Innovative Educational and Methodological Complex) "Ecology: Constructing the Biosphere", developed in 2008 by D. A. Shabanov, A. G. Kozlenko, and M. A. Kravchenko by order of the NTFP (National Training Foundation) of the Russian Federation (more about this project is in the article "Innovation and Reality"; reasons why this complex is not used are briefly described in the column "Textbooks: Straight into the Day After Tomorrow"). This model is posted here for educational use. The model illustrates the well-known experiment of Theodor Engelmann conducted in the late 19th century. The theoretical material related to the model is in the section "Biological Effects of Electromagnetic Radiation" of the manual "Ecology: Biology of Interactions". The model simulates an experiment showing that different parts of the solar spectrum differ in photosynthetic activity. Aerobic bacteria are used in the experiment; they move toward increasing oxygen concentration in water. During the experiment, a filamentous green alga is illuminated with light that can be decomposed into a spectrum using a prism. Photosynthesis intensity is estimated from bacterial distribution near different parts of the alga. To begin, click the "Next" button. Instructions for working with the model are located at the bottom of the window; if they do not fit, they can be scrolled with the arrows on the right. Conduct investigations in different operating modes. Note differences in aerobic-bacteria distribution and explain them.