Nitrate assimilation by plants provides an excellent system for demonstrating control of gene expression in a eukaryotic organism. Describes an assay method that allows students to complete experiments designed around the measurement of nitrate reductase within a three-hour laboratory experiment. (PR)

Explains how sweet potato roots can be used for plant tissue culture for biology laboratory instruction. (PR)

Introduces activities to reinforce the concept of and problems involved with introduced, nonnative or alien species. Provides seven vignettes about seven different plant and animal species that have become or currently are near ecological disasters. (CCM)

Examines how young children in preschools use the criterion of movement to determine whether an object, in this case plants, is living or non-living. Reports that children presented a conceptual change classifying the plant as alive using explanations including dependence on environment and other functions. Includes references. (CMK)

A demonstration that can be used to illustrate diffusion and osmosis is presented. Discussed are materials, procedures, and an explanation for the effect. (CW)

Discussed is the evolution of aerobic organisms from anaerobic organisms and the accompanying biochemistry that developed to motivate and enable this evolution. Uses of oxygen by aerobic organisms are described. (CW)

Describes 38 database projects sponsored by the National Endowment for the Humanities (NEH). Information on hardware, software, and access and dissemination is given for projects in the areas of art and architectural history; folklore; history; medicinal plants; interdisciplinary topics; language and linguistics; literature; and music and music…

Describes an experimental system that allows students to observe pollen tubes in vitro and to investigate a variety of aspects of pollen tube-style interactions. One interaction provides an example of postmating reproductive isolation. (MDH)

Argues that treatment of one investigative longitudinal topic from start to finish in a high school biology class can illustrate many major ideas and concepts. Discusses ways to use various longitudinal studies of plant growth with General Biology classes. (WRM)

Describes a series of low-cost experiments to investigate the ability of seeds from different species to acquire tolerance of thermal stress. Suggests links to discussions on molecular biology, physiology, ecology, and evolution. (WRM)

School students, and their teachers, seldom have opportunities to investigate something in nature. Yet children's development, as perceived by Piaget, and historical scientists' learning, involves investigation. We acted to include these investigative responses and historic resources into our work with new science teachers. We did this in the…

Presented is an activity that may be used to help students clarify the basics of graphing while allowing individuals to collect data and perform a simple experiment. A timetable, rules for graphing, materials, procedures, and suggestions for extension activities are provided. (CW)

Reviews the history and habits of the fungus commonly referred to as the "chestnut blight." Considers the impact of the blight and efforts to control it, offers personal and cultural reflections on the blight, and gives tips for incorporating the information into cross-disciplinary lessons. Contains 17 references. (WRM)

Provides rich description of the biological diversity found in a 30-mile section of Nebraska known as the "biological crossroads." Argues that the seven major associations of the Niobrara River valley provide a great classroom. Includes a complete listing of plant species. (DDR)

Background information on the methods and varieties used to demonstrate the cultivation of plants without the use of chemical pesticides is provided. Discussed are species and variety selection, growing plants from seed and from seedlings, soil preparation, using cuttings, useful crops, and pest control. (CW)