Identified classroom variables (teacher variables and classroom climate) which are related to changes in high school students' conceptions of the nature of science. Results discussed are based on data collected over a two-year period from 18 biology teachers and their 409 students. Implications for science instruction are addressed. (JN)

Describes a unit on macromolecules that has been used in the 12th grade of many Israeli secondary schools. Topic areas in the unit include synthetic polymers, biological macromolecules, and nucleic acids. A unit outline is provided in an appendix. (JN)

Summarizes the current state of genetics, highlighting major historical events in the development of the field and discussing topics related to introns ("silent" or noncoding base sequences in eucaryotic genes) and exons (the coding parts of DNA). (JN)

Discusses (1) types of fires; (2) how to extinguish them; (3) how to use a hand-held fire extinguisher; and (4) what to do in case of fires in schools. (JN)

Discusses highlights in the development of genetic engineering, examining techniques with recombinant DNA, legal and ethical issues, GenBank (a national database of nucleic acid sequences), and other topics. (JN)

Presents a scenario related to the disposal of potentially dangerous ether. Several suggestions for dealing with peroxide-forming compounds are included. (JN)

Background information, procedures, and results obtained are provided for two experiments. One measures the field strength at a particular moment to an accuracy with a level of error less than two percent. The other gives continuous readings or potentials in the field. (JN)

Describes paleontological studies of trace fossils (the impressions that record the animal's activity) such as dinosaur footprints. Discusses the importance of findings to our knowledge of dinosaur social behavior and community structure. Also tracts evolution of behavior from the Upper Triassic through the Upper Cretaceous, building evidence of…

Discusses the subjective relativity of the term "up" and its relationship to an observer's acceleration. Provides examples from amusement park rides and literature, and describes a demonstration using a Fletcher's Trolley. (JM)

Discusses the relationship of gravity, coefficient of friction, surface area, and Newton's second law to explain the physics involved in downhill skiers being able to move faster than sky divers in free fall. (JM)

Presents a new, recommended format for the periodic table which does not use the letters A and B to designate subgroups of elements. Also describes events leading to the adoption of this recommendation. (JM)

Discusses structure, phase transitions, and atomic volumes of the various period table families taking into account modern x-ray methods to the structure of the elements and to phase transformations as a function of temperature and pressure. Includes table and graph of atomic values at one atmosphere and room temperature. (JM)

Background information, list of materials needed, procedures used, and discussion of typical results are provided for an experiment on the thin layer chromatography of chlorophyll pigments. The experiment works well in high school, since the chemicals used are the same as those used in paper chromatography of plant pigments. (JN)

Discusses the life cycle of a fluke to illustrate a form of larval reproduction which occurs in many trematode flatworms. Polyembryony, production of many embryos by the breakup of the one early embryo that resulted from sexual reproduction, is considered. (JN)

Relates the experiences of a naive computer-using teacher attempting to integrate the microcomputer into a course unit on human anatomy. Based on these experiences, advice is offered to others who are incorporating computers into their courses for the first time. (JN)