In learning genetics, many students misunderstand and misinterpret what “dominance” means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that enzyme-producing alleles usually show complete dominance. For genes producing nonenzymatic proteins such as collagen or hemoglobin, the amount of product matters, and dominance relationships are more complicated. Furthermore, with hemoglobin, dominance can change depending on what aspect of the phenotype is being studied and on the environmental conditions. X-linked genes are a special case, whether enzymatic or not. Because of X-chromosome inactivation, only one X-linked allele can be active in a cell, which means that the concept of dominance cannot be applied at the cellular level. Instead, a type of dominance is demonstrated at the individual level; but even so, dominant traits may fail to be expressed, and recessive traits can be expressed. Teaching not only what is happening but why it's happening will give students a deeper understanding, not only of dominance relationships, but of the underlying cellular processes as well.

Graduate teaching assistants (GTAs) are often used as instructors in undergraduate introductory science courses, particularly in laboratory and discussion sections associated with large lectures. These GTAs are often novice teachers with little opportunity to develop their teaching skills through formal professional development. Focused self-reflection about end-of-semester teaching evaluations may be an important informal supplement to teacher training. To inform this practice, we explored the instructional behaviors that undergraduates perceived as most important for GTAs' teaching effectiveness in laboratory courses. In spring semester 2012, 1159 undergraduates in freshman-level biology lab courses rated their GTAs on 21 instructional behaviors, the GTAs' teaching effectiveness, the amount the student learned, and their expected grade in the laboratory. Using linear mixed models, we found that instructional behaviors related to the categories of teaching techniques and interpersonal rapport best predicted student ratings of GTAs' teaching effectiveness. GTAs or other novice teachers can use this information to identify specific areas for instructional improvement when considering student feedback about their teaching.

We present a guided-inquiry biology lesson, using the plant—rhizobium symbiosis as a model system. This system provides a rich environment for developing connections between the big ideas in biology as outlined in the College Board's new AP Biology Curriculum. Students gain experience with the practice of scientific investigation, from designing and conducting experiments to making claims based on the data they collect. We include one example of a piloted classroom experiment that can easily be modified to test a variety of interesting ecological and evolutionary hypotheses.

Hands-on activities with live organisms allow students to actively explore scientific investigation. Here, I present activities that combine guided inquiry with direct instruction and relate how nutrition affects the physiology and behavior of the common housefly. These experiments encourage student involvement in the formulation of experimental design, promoting engagement in the learning process. These activities are suitable for both postsecondary education and high school classroom settings and highlight National Science Education Standards, particularly by promoting inquiry-based learning and communicating science explanations.

Recent scientific studies are providing increasing evidence for how microbes living in and on us are essential to our good health. However, many students still think of microbes only as germs that harm us. The classroom activities presented here are designed to shift student thinking on this topic. In these guided inquiry activities, students investigate human—microbe interactions as they work together to interpret and analyze authentic data from published articles and develop scientific models. Through the activities, students learn and apply ecological concepts as they come to see the human body as a fascinatingly complex ecosystem.

Recent reform initiatives in undergraduate biology call for curricula that prepare students for dealing with real-world issues and making important links between science and society. In response to this call, we have developed an issues-based laboratory module that uses guided inquiry to integrate the concepts of animal behavior and population biology into an issue of both local and global relevance. The issue associated with this module is “What should be done about invasive crayfish?” Students investigate plausible reasons why crayfish are often successful invasive species through hypothesis testing, collection of behavioral data on live crayfish, and quantitative reasoning. Students also consider economic and environmental impacts of invasive species on local and global ecosystems. We implemented this module in a large introductory biology course and conducted survey research to evaluate the module's potential to serve as an interesting and valuable learning experience for undergraduate biology students.

Providing both introductory information and biosecurity protocols in laboratory, farm, and field settings is central to student learning and safety. However, even when clear protocols are provided, students do not fully understand the consequences of their actions. We present a crime scene that requires evidence investigation to improve basic skills and inquiry to identify biosecurity breaches. The crime-scene format engages students and encourages critical thinking about the negative effects of actions when working in various environments. This approach not only improves student skills through forensic microscopy but advances student retention of biosecurity requirements.

As a science teacher, I regularly use outside reading assignments (e.g., news articles) to help develop my students' understanding of topics addressed in my anatomy class. However, I have found that in simply reading texts, students often fail to (1) understand the context of the science discussed, (2) make the connections between ideas represented in the reading and those presented in class, and (3) appreciate the science that is being discussed. To better support my students' reading, I needed to structure their reading to direct them toward key ideas and prompt them to process the information deeply, to make connections between their readings and the concepts learned in class, and to understand the science content in context. To address these needs, and to help increase my students' science comprehension and encourage their thinking while reading, I turned to a language arts strategy called Literature Circles. Here, I describe my use of this successful strategy and provide resources to support other teachers who want to employ outside readings and/or Literature Circles in their own teaching.

Technology use in science classes can enhance lessons and reinforce scientific content. The creation of multimedia projects is a great way to engage students in lessons about estuarine ecosystems. In this activity, students can learn about estuarine organisms and use their creativity to write a story, create artwork, and develop a multimedia presentation about the organisms using the Microsoft PowerPoint program. The projects can then be shared to inform others about life in an estuary.