Polychlorinated biphenyls (PCBs) are a family of synthetic chemicals consisting of carbon, hydrogen, and chlorine atoms. PCBs have been produced commercially since 1929 in hundreds of industrial applications. Their continued production in the United States was phased out in the late 1970s, and strict disposal guidelines were regulated as adverse…

This article describes a thought-provoking lesson that compares various arrangements of lamp-battery circuits to help students develop the motivation and competence to participate in scientific discourse for knowledge construction. Through experimentation and discourse, students explore concepts about voltage, current, resistance, and Ohm's law.…

A practical magnetotropism experiment with seeds is presented. The procedures, needed controls, and observations of results are described. (DF)

To integrate a research/discovery component into one course, an experiment using the sea urchin embryo system is introduced because the teacher manages only one organism and students provide the variables. The materials, handling methods, and experimental methods of the experiment are described. (YP)

At Oklahoma City Community College, they have developed gel electrophoresis activities that support active learning of many scientific concepts, including: pH, electrolysis, oxidation reduction, electrical currents, potentials, conductivity, molarity, gel electrophoresis, DNA and protein separation, and DNA fingerprinting. This article presents…

Discusses who has the right to determine the use of animals in scientific research which includes medical experimentation and the toxicity testing of compounds, ranging from pesticides to cosmetics. Provides a list of questions for consideration and discussion. (RT)

Describes how plants can be produced by cloning by using tissue culture methods to mass-produce rare native prairie plants and trying to transfer some of the genetic characteristics of native grasses into cultivated cereals. The experiment was conducted at South Dakota State University. (HM)

Provides information on collecting and maintaining termites and for using these insects in behavioral studies (trail following, recognition, food choice, reproductive behavior, and behavior in a magnetic field) and termite control experiments (preventive construction techniques, termite repellents, using soil or wood pretreatment, and the bait…

Describes an inexpensive device (around $8.00) for measuring light. The circuit used includes five resistors, three small capacitors, a cadmium sulfide light sensor, two integrated circuits, and two light-emitting diodes. The unit is constructed on a small perforated circuit board and powered by a 9-V transistor radio battery. (JN)

Described is the construction of a density gradient column and several density related experiments which can be performed with the device. (SL)