Described is the construction and use of an osmometer that is low in cost, easy to make, and durable. Materials needed and procedures are outlined. Diagrams show an assembled instrument and individual parts. (RT)

Summarizes research on inquiry and investigative strategies for teaching laboratory science. Concludes that meaningful laboratory instruction is distinguished by: student engagement in science inquiry processes, student manipulation of experimental materials, and the experiential teaching of specific scientific concepts. (RT)

Describes exercises in which tabs from aluminum beverage cans are used to introduce principles of classification, biostratigraphy, and evolution. Provides diagrams which represent dorsal and ventral views of species and a table which graphs units of time in relation to species duration. (RT)

Described is a laboratory study designed to demonstrate loss of vegetation, alterations in the species composition of a community, and the impoverishment of a community with respect to desirable food plant species when herbivore feeding exceeds the rate of vegetation regrowth. The laboratory uses a classroom aquarium. (CW)

Described is an experiment for measuring the coefficient of restitution with a meter stick, balls of different types, and scraps of material for the plates. Provides the experimental procedure and an apparatus diagram. (YP)

Discusses procedures for teaching basic soil morphological concepts using soil cores collected along a toposequence. Describes materials and methods for collecting, laboratory use of cores, and student evaluation results. Shows a table of criteria used to describe soils for profile descriptions. (RT)

Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)

Discusses and suggests some solutions for three problems related to chemistry laboratory management, including disappearance of teaching assistants, check in/out procedures, and slow students. (YP)

Provides a step-by-step guide for a simple experiment to measure the approximate percentage of oxygen found in the air that we breathe. Includes background theory, working drawings, chemicals needed, list of supplies, experimental procedure, data evaluation method, and suggestions for extended study. (Author/JJK)

A mechanical analogy between the microscopic motion of a charged carrier in an ordinary resistor and the macroscopic motion of a ball falling along a slanted board covered with a lattice of nails is introduced. The Drude model is also introduced to include the case of inelastic collisions. Computer simulation of the motion is described. (KR)

The classification scheme for periodontal diseases developed in 1989 is discussed, and technologies, both surgical and nonsurgical, for prevention, control, and regeneration of periodontal tissues are described and compared. Research needs are discussed. (MSE)

A procedure for purifying DNA using either bacteria or rat liver is presented. Directions for doing a qualitative DNA assay using diphenylamine and a quantitative DNA assay using spectroscopy are included. (KR)

A laboratory experiment designed to provide rapid, inexpensive student exposure to pharmacogenetics in drug elimination and patient therapy is described. The test, performed on students, determines expression of a drug metabolism enzyme following ingestion of a probe drug. (Author/MSE)

Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)

Presents some simple demonstrations that students can construct for themselves in class to learn the difference between diffusion and convection rates. Uses cabbage leaves and gelatin and focuses on diffusion in ungelified media, a quantitative diffusion estimate with hydroxyl ions, and a quantitative diffusion estimate with photons. (DDR)