For teachers, a common difficulty when introducing scientific thinking is finding ways to engage the participation of the students. Because most scientific problems require at least some specialized knowledge to formulate and solve, it can be hard to go beyond merely discussing the steps of the scientific method and illustrating them with the…

The near daily news reports on food-borne diseases caused by contaminated produce, dairy, or meats suggests to the public that the safety of the U.S. food supply is in jeopardy. These reports, as well as a general distrust in federal agencies due in part to mad cow disease and toxigenic forms of "E. coli" in ground beef, have resulted in an…

Describes the sturcture and asexual reproduction of the fungus Pilobolus and outlines a number of experiments with this organism that are suitable for secondary school biology students. (JR)

Provided are two experiments which deal with the formation of callus and embryos from tissue culture of carrot roots. Outlined are the purpose, materials, procedure, and results for each. (RT)

Discusses the impact of using laboratory exercises and queries on developing student sensitivity to bioethical issues. Examples of these questions and the responses of students of an introductory life science course at Worcester Polytechnic Institute, Worcester, Massachusetts are presented. (HM)

Describes an apparatus that facilitates the quantitative study of fermentation in yeast by allowing simultaneous measurements of fermentation rates in several treatments and a control. Explains a laboratory procedure in which the apparatus is used. Several suggestions for further investigations are included. (Author/RT)

Described is a laboratory procedure for teaching seed stratification. Materials, methods, results, and applicability of the experiment are explained. Diagrams showing the percent of total germination as a function of stratification time and the germination rate of stratified seeds are included. (RT)

Describes two simple procedures allowing students to experiment with living membranes and to relate their results to fundamental membrane structure. Provides instructions for determining the effects of temperature and organic solvent stress on cellular membranes, and spectrophotometric analysis. (RT)

Described are projects and observations that can be conducted with the laboratory mouse to study mammalian growth and development. (RH)

A number of activities are described by which a class can collect biological data about the students in the class. Brief instructions are given. (RH)

Two statistical tools, the Chi-square and standard error approaches, are compared for use in Mendelian genetics experiments. Although the Chi-square technique is more often used, the standard error approach is to be preferred for both research investigations and student experiments. (BB)

Described is a project designed to determine the kinds and types of science laboratories located in and around Yolo County, California. Summarized are some of the sites visited by the investigator and some of the impressions of those facilities. (CW)

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)

A modification of the Ames test for detecting carcinogens and mutagens using a strain of bacteria is described. A suggestion is given for checking the correctness of procedures by using particular hair dyes which have been shown to be mutogenic. (Author/SA)

Describes a laboratory exercise which applies Koch's Postulates to a plant disease, bacterial speck. Includes an explanation of Koch's Postulate, list of equipment needed, advance preparation, outline of the three-week activity, and variations of the laboratory exercise. (DS)