Presented is an exercise for high school students which illustrates the principle and practice of measuring energy flow through a community. Included are worksheets, instructions, a flow diagram, and a list of ecosystem parameters. (Author/CW)

Presents a procedure by which cytokinins are used to induce a population of dividing and differentiating cells on the cut surface of the roots of an intact plant. Includes the method used, results, and suggestions for a variety of variables that may be tested. (RT)

Described are three experiments on the photometric, Gaussian, and image-forming properties of a helium-neon gas laser. Details of the experimental method and typical calculations with diagrams and graphs are provided. (YP)

Discusses a laboratory exercise simulating the paths of light rays through spherical water drops by applying principles of ray optics and geometry. Describes four parts: determining the output angles, computer simulation, explorations, model testing, and solutions. Provides a computer program and some diagrams. (YP)

Discussed is the historic development of Snell's law and derivation of the law without using mathematical expressions. Describes laboratory procedures using diagrams. (YP)

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)