Describes the life cycle and requirements of midges. Discusses larval substrate preferences, swimming behavior and distribution, developmental rates, temperature tolerances, egg hatching, swarming flights of adults, species composition within a sampling site, and developing a reference collection by rearing larvae. (CW)

Describes how plants can be produced by cloning by using tissue culture methods to mass-produce rare native prairie plants and trying to transfer some of the genetic characteristics of native grasses into cultivated cereals. The experiment was conducted at South Dakota State University. (HM)

Describes a game that illustrates the principles of population genetics and helps explain the occurrence of evolution through changes in gene frequencies. Demonstrates the importance of genetic variability in evolution: winning is achieved by a player's species becoming "completely heterozygous" for six characteristics. Players move directed by…

An activity that can be used to teach plant nutrition and the use of hydroponics is presented. Materials and procedures are discussed. Possible topics for science projects are suggested. (CW)

The director of the Marine Systems Laboratory of the Smithsonian Institution discusses steps in developing ecological models. The following topics in using an aquarium for the ecosystem are described: lighting, water motion, water quality and filtration. Presents information on choosing living organisms for the ecosystem. Describes potential…

Provides a graphing exercise designed to help students understand the coevolution of the physical environment and the biosphere during the last four billion years of Earth's history. The ideas are based upon the Gaia theory, which is the belief that the Earth is a self-regulating network of interdependent physical and biological systems. (ZWH)

Described are a method of cultivating Euglena, a method for presenting and solving mole equations, and a design of a simple solar collector. (SL)

Reviews a fictitious case study used as a values-clarifying teaching strategy for students of human genetics and bioethics. (SL)

Discusses one mechanism proposed for the two-step initiation/promotion scenario of the development of cancer called oncogenes and a possible alternate mechanism that may prevent tumors from developing. Uses the example of retinoblastoma to illustrate the mechanisms. States that these mechanisms may not be caused by the activation of oncogenes. (CW)

A procedure for extracting DNA from yeast using common reagents and equipment is given. Suggestions for variations are provided. A second activity for building a model of DNA from toothpicks is included. (CW)

Described is the integration of individual student inquiry investigations into a seventh grade life-science course. Student projects and problems encountered are discussed. (SL)

Described is a science activity for impressing upon students the complexity and the delicacy of interactions between organisms and the environment. (Author/SL)

Describes how the study of hyaline membrane disease is included in a physiology or comprehensive health survey course at Wilmington High School, Wilmington, Massachusetts. (HM)

Described is a science activity which illustrates the principle of uncertainty using a computer simulation of bacterial reproduction. Procedures and results are discussed. Several illustrations of results are provided. The availability of a computer program is noted. (CW)