Outlines a laboratory activity which takes place at the zoo and helps make some of the important aspects of evolution more concrete. Includes the principles of adaptation, variation within a species, types of evolution, and predicting future evolutionary trends. Provides a student worksheet. (RT)

This booklet is a revised edition of Donovan Johnson's "Paper Folding for the Mathematics Class" (ED 077 711). It begins with directions for folding basic constructions such as as a straight line, the line perpendicular to a given line passing through a given point, and the bisector of an angle. Subsequent chapters cover concepts related to…

The use of paper folding to demonstrate polygons which give plane tessellations, conic sections, and the solutions to several problems is described. (SD)

Describes a project for junior high and senior high school students designed to safely preserve hard-bodied marine invertebrates. Details the materials and procedures used in this technique. Stresses the use of non-toxic solutions and producing a lifelike specimen. (CW)

Offers suggestions for the development of a laboratory assistant program. Includes guidelines and factors to consider in the selection process and in the training program. Discusses the advantages of this type of program for both students and teachers. (ML)

Describes a design for a hand-held conductivity tester powered by a 9V battery that gives semi-quantitative results for aqueous electrolyte solutions of concentrations ranging from 0.001 M to 0.1 M. The tester uses a bar-graph LED driven by an LM3914 integrated circuit to indicate the level of conductivity. A list of parts, procedures, and results…

Definitions for the terms open-ended, problem solving, and investigations are considered. The interaction between these terms and teaching styles are discussed. Student influences over the learning process in this type of investigation are examined. (CW)

Gives some ideas for studying and growing crystals in the classroom and home as well as some background information to help integrate these ideas into an existing science curriculum. Discusses three activities including common household materials and laboratory procedures. (CW)

This article takes a critical look at practical work in school science and the often extravagant claims that are made for it. A case is made for a more rigorous, theory-driven approach to practical methods. (Author/CW)

A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

Discusses how to address the concept of chemical equilibrium through the use of thermodynamic activities. Describes the advantages of setting up an equilibrium constant in terms of activities and demonstrates how to approximate those activities by practical measures such as partial pressures, mole fractions, and molar concentrations. (TW)

Reports on the teaching of recombinant DNA technology in high school biology courses. Explains reactions of the public, students, and colleagues to the molecular genetics unit. Indicates equipment, curricular materials, training, workshops, and availability. (RT)

Discussed is the integration of microcomputers into the science laboratory curriculum. The approach provides an exposure to important aspects of computer technology while preserving concrete experiences provided by hands-on laboratories. (CW)

Presents several fun activities and teacher demonstrations which simplify terms and condense science concepts for teaching about the lever, wedge, wheel and axle, screw, pulley, and the inclined plane. Includes objectives, materials, procedures, suggested follow-up assignments, and diagrams. (RT)