This paper reports on findings from an analysis of trait-formation tasks in the genetic sections of high school biology textbooks. Drawing on studies exploring a range of problems in students' explanations of trait formation, we investigated trait-formation tasks and analysed their potential for knowledge integration and multi-level mechanistic…

School science practical activities have been criticised for exposing learners to a series of phenomena disconnected from the conceptual frameworks needed to understand them. Such activities are successful in the "domain of observables" but not the "domain of ideas". Few resources exist for classroom teachers wishing to improve…

Our out-of-school practical exercise was designed to bring upper secondary school students in contact with one of the most exciting and expanding topics in biology today: epigenetics. In school, students only study the basics in genetics and the respective investigation techniques as provided by the syllabus. For a practical exercise in…

Process diagrams are important tools in biology for explaining processes such as protein synthesis, compound cycles and the like. The aim of the present study was to measure the ability to solve process-diagram problems in biology and its relationship with prior knowledge, spatial ability and working memory. For this purpose, we developed a test…

Biological flight mechanics is typically taught in graduate level college classes rather than in secondary school classes. We developed an interdisciplinary unit for advanced upper-level secondary school students (ages 15-18) to teach the principles of flight and applications to biological systems. This unit capitalised on the tremendous…

This paper is based upon a laboratory exercise designed for biology students in secondary schools or those taking introductory biology laboratory courses in colleges and universities. This exercise requires a set of calipers, a calculator and populations of snail shells collected either from the wild or obtained from a biological supply house. The…

This study compares two methods of instruction in practical school biology. The content remains the same but two teaching methods are used, one based on workstations (Group 1) and the other a conventional approach (Group 2). The content was a regular 9th grade syllabus issue: visual perception. Method 1 included a phenomenological introduction,…

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)

Suggestions for instructional improvement are provided in two topic areas. Explains the use of models in helping students to visualize selected concepts in genetic engineering and recommends the use of tropical tuber crops for encouraging students to conduct practical investigations. (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)

Clearing is a simple and rapid technique in which 75 percent lactic acid is used to remove pigments and cytoplasmic contents of fresh leaves, enabling microscopic view of various internal leaf layers. Procedures for using the technique (which helps students gain a more thorough understanding of plant anatomy) are given. (DH)

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)

Explains how simple models of easily assembled materials can help teach the workings of human joints. Provides specific suggestions for demonstrating the structure and operation of fixed joints, slightly movable joints, and freely movable joints. (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)