A theory of motor skill performance in dentistry is presented, and studies of its use in improving preclinical laboratory instruction are reviewed. The model explains how the mind directs the hand so specific outcomes can be achieved, a theory which can be operationalized in instructional design. (MSE)

Described is an activity in which students learn how a battery produces electricity, why at least one electrode is destroyed when electricity is produced, and how electrolytes and temperature affect the process. Needed materials and directions for building a battery are listed. (KR)

Various aspects of photography using both transmitted and reflected light microscopy are described. Microscope configuration, preparation of samples for photomicrography, and the use of black/white or color film are discussed. (KR)

Alternatives to the traditional unknown tests that permit a clear and unequivocal differential identification decision between Bacillus subtilis and Bacillus megaterium are presented. Plates of Phenylethyl Alcohol agar with Blood (PEAB), slants of Bile Esculin agar and plates of DNA agar are used. The materials, methods, results, and conclusions…

Activities that consider the courtship behavior and mating patterns of millipedes are presented. The functional significance of a behavior that has evolved through indirect competition between males is discussed. The procedures for seven experiments, results, and interpretations are included. (KR)

An activity simulating natural selection in which wild birds are predators, green and brown pastry "baits" are prey, and trays containing colored stones as the backgrounds is presented. Two different methods of measuring selection are used to describe the results. The materials and methods, results, and discussion are included. (KR)

Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

Describes an experimental procedure that can be used to determine the potential bacterial contamination of stagnant water in emergency laboratory eyewash bottles. Contains 11 references. (WRM)

Reports on the design and testing of student-directed investigations for use in large enrollment biology courses. Describes a set of experiments that include the preparation and study of the enzyme tyrosinase. (DDR)

Details a lesson that utilizes trigonometric identities to determine the optimal angle between the atoms of covalent bonds. Generates a proof of the optimal angle for a molecule with four identical atoms bonded to a central atom that has a complete valence shell. (DDR)

Begins with the procedure and results from an investigation on the effect of fluoride on the reaction between eggshell (substitute teeth) and dilute ethanoic acid. Describes an elegantly modified and improvised apparatus. (DDR)

Provides an exercise designed to give students an appreciation for the genetic basis of behavior. Employs the phenomenon of glucose aversion as an example of evolution by mutation and accelerated natural selection, thereby revealing one of the ways in which organisms adapt to human interference. (DDR)

Introduces an investigative microbiology laboratory activity emphasizing critical thinking and experimental design in which students isolate and characterize a bacterium from a specific habitat. Explains the procedures of the laboratory including safety, sample collection, and isolation. (YDS)

Presents an experiment in which students use laboratory data to calculate the interphase mass transfer coefficient for a fluid passed over a sphere and obtain correlations for solid-gas mass transfer. Students develop a realistic mathematical model to describe the sublimation process. (DDR)