Suggests ways in which hens' egg vitelline membranes can be used to demonstrate cell traction effects. Reviews procedures for using and culturing the membranes and identifies topic areas for student projects. (ML)

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)

Presents a classroom experiment that demonstrates the directional sensitivity of the human ear. Outlines the activity's procedures and provides a diagrammatical view of the experimental arrangement. Also included is an analysis of the expected results. (ML)

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)

Background information on the biology of aphids is supplied. Using this information in a wide variety of investigations, many involving equipment and techniques available in the school laboratory, can be carried out. An appendix lists possible projects. (Author)

Briefly describes some of the more recent developments in the use of human hairs for such instructional purposes as observing barr bodies and chromosomes, and for culturing to produce cells of both epithelial and fibroblastic morphology. Three main hair categories are also described. (JN)

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 the experimental procedures for isolating fungi and demonstrating their tolerance of fungicides such as creosote and organic mercury. (JR)

Describes experiments using crude isolated chloroplast fractions which demonstrate some aspects of the photosynthetic light requiring process and a number of factors affecting them. These experiments are suitable for senior high school and college courses in biology. (JR)

Experiments conducted on wheat and barley grains to analyze activities of alpha- and beta-amylase enzymes. Gibberellins were used exogenously. Techniques are described in detail. Results on different cultivars revealed that beta-amylase was not an invariable result of imbibition. Techniques employed can be used by school students. (PS)

The shore crab (Carcinus maenas) is an excellent subject for school study, both in the field and the laboratory. It is easily collected and maintained and can be used for a wide range of investigations. Some background details are given and possible areas of investigation suggested. (Author)

Offers suggestions for teaching some aspects of water economy in plants. These include diffusion/osmosis, water transport, the part played by turgor in structural support, and its implications for plant organs or whole plants. Several practical demonstrations/experiments are also described. (JN)

Describes modifications of a Nuffield experiment demonstrating oxygen transport by blood since the current experiment more often than not produces unsatisfactory results. Includes experimental modification, instructional strategy, assembly of equipment, and a brief discussion. (JN)

Techniques for examining terrestrial and aquatic microorganisms using flattened glass capillaries are described. Capillaries can be left in natural or artificial environments for appropriate periods of time and removed for direct microscopic examination. Examples of organisms observed using the technique are given and suggestions made for wider…