New Light on Phototaxis and Phototropism

 

Charles D. Drewes

Tested Studies in Laboratory Teaching, 2004, Volume 25

Abstract

This mini-workshop deals with ultra-bright light-emitting diodes (LEDs) and their applications to classroom investigation or student research. Features of ultra-bright LEDs that make them highly useful for general biology applications include: (a) unbreakable bulbs; (b) extremely long bulb-life; (c) very low heat production and low power consumption; (d) intense, highly localized light output; (e) availability in multiple colors with narrow spectral outputs; (f) inexpensive; (g) battery or A.C.- power options; and (h) safe, easy assembly. Potential applications for classrooms and student research include investigations of color sensitivity of invertebrate phototaxis (e.g., responses to blue versus red light), as well as blue-light-mediated phototropism responses in plant seedlings. Technical information is also included about LEDs (Fig. 1), circuit configuration, power supplies, and relevant photobiology research.

Keywords:  phototropism, phototaxis

University of Nevada, Las Vegas (2003)