Describes a constant-temperature observation chamber and includes instructions on constructing the apparatus. Suggestions for use are given as well as problems that might be encountered. (Author/SA)

Recommendations are given for obtaining high quality preparations of chromosomes with relatively little equipment using an improved Feulgen-squash technique. (Authors/SA)

Presents a method for microscopically examining cytoplasmic streaming in root cells, and physiologically examining the delivery of ions to the xylem exudate. The expected result does not occur and the authors believe that students learn to re-examine the assumptions, thereby increasing their skills in scientific inquiry. (Authors/SA)

Discusses various aspects of in-service training and the design of self-instruction material. Special reference is given to materials for application in various places but developed at a central location. Results are given of the use of experimental materials in medical laboratories in The Gambia. (Author/SA)

Described is the generative learning strategy, an approach which encourages pupils to discuss their out-of-school ideas about plant breathing, drinking, wood production, soil, minerals, and leaves, and assist them in linking appropriate ideas together to form an explanation of the origin of plant materials. (CW)

Discusses the important concepts involved in problem solving. Presents a chain representation of problem solving and gives an example of the application of this method. Provides a strategy for teaching controversial issues in a science classroom and gives an example of the implementation of the strategy. (CW)

Presented is one of a series of articles designed to help science teachers keep current on ideas in specific areas in biology. Contained is information on how plants use light for growth, seed germination, and flowering. (PB)

Presented is one of a series of articles designed to help science teachers keep current on ideas in specific areas of biology. This article provides information about ion transport in plant cells. (PB)

Materials and methods for studying the functioning and responses of stomatal guard cells are described. (PB)

Described are some experiments on geotropism that may be done using dandelions. (PB)

Presented are some suggestions and information designed to increase the biology teacher's awareness of the potential for participation in discussion by each individual pupil in his/her class. (PB)

Traditional and novel uses of enzymes and microbes in the baking, brewing, and dairy industries are described. Cheese, yogurt, baking, brewing, vinegar, soy sauce, single-cell proteins, enzymes, food modification, vanilla, citric acid, monosodium glutamate, xanthan gum, aspartame, and cochineal are discussed. Industrial links with firms involved…

An update on the changes in the infection pattern of the HIV virus in the United Kingdom and the United States and comments on misunderstandings about how HIV is spread in developed countries are presented. The implications for teachers in both countries are discussed. AIDS education resources are listed. (KR)

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)

Two representations useful in teaching transmission genetics are described. Details of the representations and problem solving using these instructional aids are discussed. The importance of developing representations which help remedy specific difficulties that students commonly encounter is stressed. (CW)