Presents information that gives a methodological background to the concept of food webs. Stresses the importance of calibrated techniques in ecological research and explains direct methods for studying animal diets. Exercises for gathering first-hand data on bird diets and analyzing secondary data on mammal diets are suggested. (ML)

Describes an experiment designed to introduce students to chromatographic techniques. Also describes a teacher demonstration in which leaves obtained during the spring and fall are analyzed using chromatography. Procedures for both the experiment and the demonstration are outlined. (JN)

Thin slices of potato can be used to demonstrate the presence of protein, carbohydrates, and nucleic acids at the cellular level. Procedures and materials are provided for these simple tests. Also indicates that the presence of fat can be readily seen by staining avocado with Sudan red or Sudan black. (Author/DH)

Provides procedures for the study of osmosis and anthocyanin pigments utilizing wet mount techniques with purple onion. Suggests several activities using this preparation. (JM)

Briefly describes the ecology of a deciduous forest, and suggests activities for observing and appreciating the changes that occur during the Fall. Simple experiments relating to mosses and lichens are outlined. (JR)

Describes the experimental procedures used for detecting DNA and RNA synthesis in xenopus cells by autoradiography. The method described is suitable for senior high school laboratory classes or biology projects, if supervised by a teacher qualified to handle radioisotopes. (JR)

Describes an experiment designed to provide the opportunity for studying some of the parameters affecting the stability of Vitamin C in various environments, and to acquaint the student with an experimental procedure for studying simple reaction kinetics and the calculations of specific rate constants. (Author/JR)

Describes a microbiological experiment designed to study the competition between two species of bacteria. Experimental procedures and data obtained in conducting this experiment are provided, together with a discussion of the results. (JR)

Describes the commercial applications of hydroponics, and then outlines ways in which this soilless plant culture method can be used in the science classroom and laboratory. Gives directions for making a suitable growth solution, and suggests appropriate student experiments involving hydroponics. (JR)

Provides description of an activity in which students synthesized sulfanilamide or sulfathiazole, II. The drug was then used as a chemotherapeutic agent. (RH)

A practical magnetotropism experiment with seeds is presented. The procedures, needed controls, and observations of results are described. (DF)