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Student performance in two different introductory biochemistry curricula are compared based on standardized testing of student content knowledge, problem-solving skills, and student opinions about the courses. One curriculum was used in four traditional, lecture-based classes (n ‫؍‬ 381 students), whereas the second curriculum was used in two cooperative learning classes (n ‫؍‬ 39 students). Students in the cooperative learning classes not only performed at a level above their peers in standardized testing of content knowledge and in critical thinking and problem-solving tasks (p < 0.05), but they also were more positive about their learning experience. The testing data are in contrast to much of the medical school literature on the performance of students in problem-based learning (PBL) curricula, which shows little effect of the curricular format on student exam scores. The reason for the improvement is undoubtedly multifactorial. We argue that the enhancement of student performance in this study is related to: 1) the use of peer educational assistants, 2) an authentic PBL format, and 3) the application of a multicontextual learning environment in the curricular design. Though educationally successful, the cooperative learning classes as described in this study were too resource intensive to continue; however, we are exploring incorporation of some of the "high context" aspects of the small-group interactions into our current lecture-based course with the addition of on-line PBL cases.

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The elemental constituents of biological material are of \ital concern to many disciplines of research, particularly physiology, nutrition, and medicine. It is common knowledge that certain inorganic ions must be available for plants and animals to grow, survive, and reproduce. Conversely, many ions are toxic when present in excessan axiom of primary concern to researchers in environmental pollution. The advent of the .Atomic Age. and the realization that all elements can be made radioactive, magnified the importance of ions in living material, especially in man. Chemical elements that occur in living material are commonly di\ided into two groups, major elements and trace elements, the line of demarcation being somewhat arbitrarily set at 0.01 percent of an organism (Schroeder 1965:217). or at roughly .S.OOO-1 0.000 ppm in tissue ash. However, as Schroeder points out. this distinction is not always applicable when high concentrations of trace elements occur in special cases. Some trace elementsthose having a physiological function for at least one organismare known to be essential, while othersthose for which no function has yet been discoveredare '"nonessential." Many of the "nonessential" ions accumulate in living organisms as the organisms increase in age. a phenomenon that has recently been associated with certain diseases in man (Schroeder 1965:225-226). This paper reports the concentrations of five major elements and 18 trace elements in selected body parts (blood, bones, fat, feathers, muscles, and internal organs) of 54 hen pheasants (Phasianiis cokhicus) collected from three areas in Illinois. The analyses were conducted during an investigation of the possible effects of inorganic ions on the distribution and abundance of pheasants in this midwestern state. Portions of the analyses, as well as analyses of soil, grit, and corn, have been published elsewhere under the title "Relationships between Inorganic Ions and the Distribution of Pheasants in Illinois" (Anderson & Stewart 1969). Because of their potential contribution to many areas of research, the analyses of the pheasants' body parts are presented in their entirety in this publication. So that comparisons of data may be made easilv, all tables follow the Literature Cited section. This paper is published by authority of the State of Illinois. IRS Ch. 127. Par. 58.12. William L, .\nderson is an Associate Wildlife Specialist.

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