We present a lab that enables students to test the role of genes involved in the regulation of lateral roots growth in the model plant "Arabidopsis thaliana." Here, students design an experiment that follows the effects of the hormone auxin on the stimulation of genes involved in the formation of lateral root initials. These genes, known…

Glow sticks are a popular Halloween staple familiar to most of our students. The production of light via a chemical reaction is called "chemiluminescence," and glow sticks are often used as demonstrations and experiments in the chemistry classroom to study reaction rates as a function of temperature. A black light can be used to…

Despite numerous calls for science education to be driven by authentic investigation, many laboratory experiences continue to consist of disconnected weekly units during which students carry out instructions that lead to some predetermined finding. This study developed and evaluated a pedagogical design for introductory biology labs where students…

Since the first report of electroformed micrometer-sized liposomes in the 1980s, giant unilamellar vesicles (GUVs) have generated a lot of interest in the biophysical and biochemical communities. However, their penetration rate in high school or at the undergraduate level is still limited because of the requirement of specialized materials for…

This study examines how two kinds of authentic research experiences related to smoking behavior--genotyping human DNA (wet lab) and using a database to test hypotheses about factors that affect smoking behavior (dry lab)--influence students' perceptions and understanding of scientific research and related science concepts. The study used pre and…

It is commonly recognised that practical work has a distinctive and central role in science teaching and learning. Although a large number of studies have addressed the definitions, typologies, and purposes of practical work, few have consulted practicing science teachers. This study explored science teachers' perceptions of experimentation for…

In this paper, we examined teachers' understanding of electrical concepts such as power, current and potential difference based on how these concepts were applied to understand the relative brightness seen in bulbs of different wattage under different connections--series or parallel. From the responses of teachers to a concept question, we…

In the popular press, diagrams showing the evolution of the universe begin with a great jump in size labeled "inflation." Can we explain the basic ideas behind inflation to our students who have taken our introductory physics course? Probably not. In our standard introductory physics courses, even those with special relativity, something…

Piezoelectric and pyroelectric materials are used in many current applications. The purpose of this paper is to explain the basic properties of pyroelectric and piezoelectric effects and demonstrate them in simple experiments. Pyroelectricity is presented on lead zirconium titanate (PZT) ceramics as an electric charge generated by the temperature…

Epigenetic inheritance is the inheritance of genetic information that is not based on DNA sequence alone. One type of epigenetic information that has come to the forefront in the last few years is modified DNA bases. The most common modified DNA base in nature is 5-methylcytosine. Herein, we describe a laboratory experiment that combines…

Evolution is a defining criterion of life and is central to understanding biological systems. However, the timescale of evolutionary shifts in phenotype limits most classroom evolution experiments to simple probability simulations. "In vitro" directed evolution (IVDE) frequently serves as a model system for the study of Darwinian…

In the introductory physics courses at Wartburg College, we have been working to create a lab experience focused on the scientific process itself rather than verification of physical laws presented in the classroom or textbook. To this end, we have developed a number of open-ended modeling exercises suitable for a variety of learning environments,…

The sight of a broken bat in Major League Baseball can produce anything from a humorous dribbler in the infield to a frightening pointed projectile headed for the stands. Bats usually break at the weakest point, typically in the handle. Breaking happens because the wood gets bent beyond the breaking point due to the wave sent down the bat created…

Assuming a constant mass decrease per unit surface and unit time we provide a very simplistic model for the dissolution process of spherical candies. The aim is to investigate the quantitative behaviour of the dissolution process throughout the act of eating the candy. In our model we do not take any microscopic mechanism of the dissolution…

This experimental activity aims to visualize the variations in the tension force on a rope with a mass attached to it in horizontal and vertical circular motion. The results facilitate comprehension of the effect of the direction of the radial force in changing the magnitude of the tension force. (Contains 10 figures.)