Presents investigations to explore the substrate specificity, pH, concentration, and temperature relations of an enzyme with only inexpensive commercial rennet and basic laboratory equipment. Describes how the activities were carried out with a group of 15-year-old students. (CW)

The easily obtained common snail shows interesting dietary preferences which can be the source of several simple experiments. Specific student instructions are given for quantitative and comparative studies using cabbage, lettuce, carrot, rutabaga, and onion. Suggestions for laboratory setup and further work are included. (DH)

Describes laboratory procedures for observing the progressive change deciduous leaves undergo prior to abscission. Outlines the starch test, sugar test, extraction and chromatography of pigments, and experimental results. States that obtained results enable the events of leaf senescence to be correlated with the carbohydrate economy of a tree in…

Reported is a technique for chromosome staining that is simple, rapid, inexpensive, and requires little skill for success. (PB)

Describes a method for the extraction and bioassay of natural germination inhibitors, requiring only inexpensive equipment and minimal experimental skill. The method has been used to demonstrate qualitative/quantitative differences in germination inhibitor levels in a variety of different fruits or in different tissues within a single fruit.…

A procedure is described for providing preparations of dividing cells from root apical meristems, requiring only inexpensive equipment and minimal experimental skill, and using 8-Hydroxyquinoline and Toluidene-blue as a chromosome stain. The method has been sucessfully tested in schools and yields permanent preparations of adequate quality for…

A method for demonstrating eutrophication that can be used as a simple illustration of the phenomenon or as a basis for problem-solving activities is presented. A sample worksheet with procedures for this activity and discussion questions is included. (Author/KR)

Presented is a cytogenic technique which enables students to produce preparations of dividing cells. Described are materials, methods, typical results, and assessment for this activity. The usefulness for a wide range of ages and abilities is stressed. (CW)