遗传学实验中SSR标记的应用实践

该实验是科研成果转化为实验教学设计的一个成功案例,建立了植物DNA指纹检测和父本鉴定技术。通过本实验,学生可以掌握PCR技术、DNA提取和电泳检测等实验技术,巩固关于基因位点／等位基因、纯合体／杂合体、二倍体／三倍体、孟德尔遗传规律和DNA指纹图谱等多个（对）重要的遗传学概念,提高学生学习遗传学的兴趣。     

Denying Genetic Causality

This edited volume of essays presents a countermainstream view against genetic underpinnings for cancer, behavior, and psychiatric conditions.This edited volume is a project from the Council of Responsible Genetics, a private organization based in Cambridge, Massachusetts, whose mission, as stated on its website, includes as one of several goals to “expose oversimplified and distorted scientific claims regarding the role of genetics in human disease, development and behavior.” This book represents such an effort. Editors Krimsky and Gruber are chair and president/executive director, respectively, of the organization and appear to have solicited contributions to the book from affiliates and other colleagues. Fewer than half of the 16 chapters are written by active laboratory scientists, however, and as a result, the book suffers from arguments clouded by imprecise use of terminology and preconceptions about genes and their functions. One might consider this book, or parts thereof, for an advanced undergraduate genetics class in which positions counter to the mainstream scientific view are presented and evaluated, and in which students are challenged to critically assess the quality of support for all arguments.The general theme of this book is to question the role of genes (and reproducible molecular mechanisms, more broadly) in cancer, behavior, psychiatric disorders, evolution, and other phenomena. One chapter promotes the tissue organization field theory (TOFT) against the somatic mutation theory of cancer. TOFT was proposed by the chapter authors in 2011 (Soto and Sonnenschein, 2011 ) but has not found traction and has garnered little attention beyond an initial refutation (Vaux, 2011 ). The authors assert that cancer is a disease of development and tissue repair primarily from environmental exposures and independent of genetic changes. Most cancer researchers agree that environmental factors can trigger cell growth but that ensuing mutations complete the picture in the genesis of malignancies. This chapter would be a good starting point from which one could assign students to explore papers cited in the Cancer Genome Atlas database, a growing resource compiling cancer genome data and subsequent validation in other systems of the effects of mutations found. In another chapter, a nonscientist author asserts that “in only a small percentage of cases are genes notable contributors to breast cancer,” implying imprecisely that only rare inherited cancer predisposition is genetic, when in fact cancer stemming from somatic mutations is also gene based. To assert that cancer stems only from environmental effects, to the exclusion of genes, overlooks the intertwining of the two arenas—radiation induces somatic mutations, for example, and estrogen mimics trigger cell division, which sets the stage for additional new mutations during DNA replication. Open in a separate windowOther sections of the book argue a lack of evidence for genetic influence on behaviors and psychiatric conditions. One chapter centers on several refuted ideas of biology and behavior (for example XYY and monoamine oxidase genotypes associated with aggression), with the intended implication that all other biological connections to behavior must be suspect. A chapter on autism accepts but downplays a partial role of genetics in the disorder, while emphasizing environmental exposures. Students exploring this topic could examine the growing literature on de novo mutations found in autism patients (Huguet et al., 2013 ), among other autism studies, to see how interlocking causes of the disorder might best explained by the available data. In the context of disorders such as schizophrenia, the book does not acknowledge or address the literature reporting genetic associations with psychiatric predispositions. In a troubling instance, a cited reference is misrepresented as refuting a genetic connection to schizophrenia; the reference in question (Collins et al., 2012 ) actually reports genome-wide association studies showing linkage of schizophrenia to particular loci (just not to the genes originally suspected). The same research group the previous month reported copy number variations associated with schizophrenia (Kirov et al., 2012 ), but this finding was not cited. Psychiatric genetics is a rich area for students to explore, and the contrarian viewpoint of the book can provide a starting point to trigger students’ delving into the literature.Genetic Explanations: Sense and Nonsense includes two chapters with assertions counter to the neo-Darwinian synthesis of evolution. One claims, fairly misleadingly, that “a growing number of evolutionary biologists … believe that macroevolution was the result of mechanisms other than natural selection.” Another states that “not genomic DNA but epigenetic environmental influences … overwhelmingly affect our health and well being.” The idea that gene regulation via environmental and epigenetic effects is somehow not reducible to genes (and that genes are therefore not central to evolution) would be an interesting subject for students to explore in the literature to see what the data actually support.This book is recommended only for use in advanced classes centered on weighing evidence and dissecting arguments in scientific controversies. The book''s countermainstream assertion of a lack of significant genetic connection to cancer, autism, schizophrenia, and other phenomena provides multiple opportunities for students to explore the scientific literature surrounding such genetic connections.     

Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in Brassica rapa Fast Plants

Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics.     

A Web Application for Generation of Random DNA Sequences with a Single Open Reading Frame: Exemplars for Genetics and Bioinformatics Education

A standard genetic/bioinformatic activity in the genomics era is the identification within DNA sequences of an "open reading frame" (ORF) that encodes a polypeptide sequence. As an educational introduction to such a search, we provide a webapp that composes, displays for solution, and then solves short DNA exemplars with a single ORFTo the Editor: We wish to bring a new Web resource to the attention of CBE—Life Sciences Education readers.When being introduced to the central dogma of nucleic acid transactions, students are often required to identify the 5′→3′ DNA template strand in a double-stranded DNA (dsDNA) molecule; transcribe an antiparallel, complementary 5′→3′ mRNA; and then translate the mRNA codons 5′→3′ into an amino acid polypeptide by means of the genetic code table. Although this algorithm replicates the molecular genetic process of protein synthesis, experience shows that the series of left/right, antiparallel, and/or 5′→3′ reversals is confusing to many students when worked by hand. Students may also obtain the “right” answer for the “wrong” reasons, as when the “wrong” DNA strand is transcribed in the “wrong” 3′→5′ direction, so as to produce a string of letters that “translates correctly.”In genetics and bioinformatics education, we have found it more intuitively appealing to demonstrate and emphasize the equivalence of the mRNA to the DNA sense strand complement of the template strand. The sense strand is oriented in the same 5′→3′ direction and has a sequence identical to the mRNA, except for substitution of thymidine in the DNA for uracil in the mRNA. It is thus more computationally efficient to “read” the polypeptide sequence directly from this strand, with mental substitution of thymidine in the triplets of the genetic code table. (By definition, “codons” occur only in mRNA: the equivalent three-letter words in the DNA sense strand may be designated “triplets.”) This is the same logic used in DNA “translation” software programs.A further constraint often imposed on dsDNA teaching exemplars is that five of the six possible reading frames are “closed” by the occurrence of one or more “stop” triplets, and only one is an open reading frame (ORF) that encodes an uninterrupted polypeptide. We designate this the “5&1” condition. The task for the student is to identify the ORF and “translate” it correctly. Other considerations include correct labeling of the sense and template DNA strands, their 5′ and 3′ ends (and of the mRNA as required), and the amino (N) and carboxyl (C) termini of the polypeptide.Thus, instructors face the logistical challenge of creating dsDNA sequences that satisfy the “5&1” condition for homework and exam questions. Instructors must compose sequences with one or more “stops” in the three overlapping read frames of one strand, while simultaneously creating two “stopped” frames and one ORF in the other. We have explored these constraints as an algorithmic and computational challenge (Carr et al., 2014 ). There are no “5&1” exemplars of length L ≤ 10, and the proportion of exemplars of length L ≥ 11 is very small relative to the 4^L possible sequences (e.g., 0.0023% for L = 11, 0.048% for L = 15, 0.89% for L = 25). This makes random exploration for such exemplars inefficient.We therefore developed a two-stage recursive search algorithm that samples 4^L space randomly to generate “5&1” exemplars of any specified length L from 11 ≤ L ≤ 100. The algorithm has been implemented as a Web application (“RandomORF,” available at www.ucs.mun.ca/~donald/orf/randomorf). Figure 1 shows a screen capture of the successive stages of the presentation. The application requires JavaScript on the computer used to run the Web browser.Open in a separate windowFigure 1.Successive screen captures of the webapp RandomORF. First panel: the Length parameter is the desired number of base pairs. Second panel: Clicking the “Generate dsDNA” button shows the dsDNA sequence to be solved, with labeled 5′ and 3′ ends. The button changes to “Show ORF.” Third panel: A second click shows the six reading frames, with the ORF highlighted. Here, the ORF is in the sixth reading frame on the bottom (sense) strand. The polypeptide sequence, read right to left, is N–EITHLRL–C, where N and C are the amino and carboxyl termini, respectively. The conventional IUPAC single-letter abbreviations for amino acids are centered over the middle base of the triplet; stop triplets are indicated by asterisks (*).The webapp provides a means for students to practice identifying ORFs by efficiently generating many examples with unique solutions (Supplemental Material); this can take the place of the more standard offering of a small number of set examples with an answer key. The two-stage display makes it possible for problems to be worked “cold,” with the correct ORF identified only afterward. For examinations, any exemplar may be presented in any of four ways, by transposing the top and bottom strands and/or reversing the direction of the strands left to right. Presentation of the 5′ end of the sense strand at the lower left or upper or lower right tests student recognition that sense strands are always read in the 5′→3′ direction, irrespective of the “natural” left-to-right and/or top-then-bottom order. We intend to modify the webapp to include other features of pedagogical value, including constraints on [G+C] composition and the type, number, and distribution of stop triplets. We welcome suggestions from readers.     

Mutation-Based Learning to Improve Student Autonomy and Scientific Inquiry Skills in a Large Genetics Laboratory Course

Laboratory education can play a vital role in developing a learner''s autonomy and scientific inquiry skills. In an innovative, mutation-based learning (MBL) approach, students were instructed to redesign a teacher-designed standard experimental protocol by a “mutation” method in a molecular genetics laboratory course. Students could choose to delete, add, reverse, or replace certain steps of the standard protocol to explore questions of interest to them in a given experimental scenario. They wrote experimental proposals to address their rationales and hypotheses for the “mutations”; conducted experiments in parallel, according to both standard and mutated protocols; and then compared and analyzed results to write individual lab reports. Various autonomy-supportive measures were provided in the entire experimental process. Analyses of student work and feedback suggest that students using the MBL approach 1) spend more time discussing experiments, 2) use more scientific inquiry skills, and 3) find the increased autonomy afforded by MBL more enjoyable than do students following regimented instructions in a conventional “cookbook”-style laboratory. Furthermore, the MBL approach does not incur an obvious increase in labor and financial costs, which makes it feasible for easy adaptation and implementation in a large class.     

Structure Matters: Twenty-One Teaching Strategies to Promote Student Engagement and Cultivate Classroom Equity

A host of simple teaching strategies—referred to as “equitable teaching strategies” and rooted in research on learning—can support biology instructors in striving for classroom equity and in teaching all their students, not just those who are already engaged, already participating, and perhaps already know the biology being taught.     

Jo Handelsman

Note from the Editor

Educator Highlights for CBE-LSE show how professors at different kinds of institutions educate students in life sciences with inspiration and panache. If you have a particularly creative teaching portfolio yourself, or if you wish to nominate an inspiring colleague to be profiled, please e-mail Laura Hoopes at lhoopes@pomona.edu.LH: You are deeply involved with the HHMI Teaching Fellows Program at Wisconsin and the Wisconsin Program for Scientific Teaching (Pfund et al., 2009 ), and you''ve coauthored a book about scientific teaching (Handelsman et al., 2006 ). How do you teach people to teach in your summer institutes?Handelsman: The HHMI Graduate Teaching Fellows Program teaches graduate students and postdoctoral fellows to apply theories of learning to classroom practice. The fellows set learning goals and assess whether they''re achieved. It''s theory, then practice.LH: Can you explain a little more about how it works?Handelsman: The program starts with eight weeks of a course, “Teaching Biology” in which the fellows learn about education principles and then practice on each other applying those principles. Then they go on to design their own materials, and finally, in the second semester, use that material in teaching students. In our qualitative and quantitative analysis of their teaching philosophy, we see little change after the first semester. But there is radical improvement after they put their ideas into practice in the second part. People learn by doing.LH: How about a specific example of how the fellows develop materials.Handelsman: There''s a choice of venues, but let''s say one picks the honors biology course. They identify a technical problem, such as explaining Southern, Northern, and Western blotting. Our fellows then develop active-learning materials to address a challenging concept and test them in the classroom, often in multiple sections of a class. They refine and retest them. Another fellow might choose “Microbes Rule,” a course developed by fellows, which teaches about bacteria, viruses, and fungi. That fellow develops learning goals about antibiotic resistance, flu, or contaminated peanut butter, and designs classroom materials to achieve these goals.Open in a separate windowJo Handelsman, HHMI Professor, Department of Bacteriology, University of Wisconsin–Madison, Madison, WI.LH: Do the teaching fellows find the work difficult?Handelsman: It''s a challenge for them to narrow down to a workable subtopic. We work with them to focus on the learning goals, asking “The students will know and be able to do what at the end of this unit?”LH: Did you learn this method of focusing on goals when you were being trained?Handelsman: No, most of us were never taught to consider goals for learning. So in training our fellows, we direct them to focus on that over and over, and ask how their plans relate to the goals. It''s backward design—think about what you want to achieve, then think about how to get there.LH: Assessment is becoming more important at universities and colleges all over the country. How do you teach the fellows to use it?Handelsman: Students design their own instruments. They develop skills to determine whether their goals are being met. We go over the tools with them repeatedly, identify potential downfalls, let them implement, and then review the results to see if they obtained the information needed to determine whether their teaching worked.LH: What kind of questions do they tend to use for assessment?Handelsman: Exam-type questions are important, whether taken as an examination or in a questionnaire. Videos of student presentations with reviewers who score on effectiveness are also useful. We ask how the fellows know if the students understood the material, and how the evidence relates to each of their learning goals.LH: How do they evaluate and incorporate input from past assessment?Handelsman: Before using an instrument for assessment, the fellows develop a rubric to score the quality of the answers. Often they decide to share this rubric with the students. They want to show the students what goal the assessment is addressing, what is an adequate answer, what is an outstanding answer. Then they discuss with their peers how to use this feedback to improve their teaching.LH: I''ve heard faculty members at other places saying that they do lots of assessment but don''t know what to do with it after they are forced to collect the information.Handelsman: I''d suggest that they do less and use it more! Not using assessment results is like designing a new experiment but ignoring your earlier results. If we have the information to improve our teaching, we should use it.LH: A lot of interviews for faculty positions ask for a teaching philosophy. It sounds like your fellows are well-positioned to answer these questions.Handelsman: Yes, they have to write their teaching philosophy several times, discuss it with the other fellows, and rewrite. The fellows have been very successful in obtaining positions.LH: Have you had undergraduate research students?Handelsman: Yes, it''s one of the most important academic activities in which students take part—anything hands-on is good, but undergraduate research is the best because it incorporates inquiry, discovery, real scientific processes. It plays into curiosity. It''s such a rewarding process to watch a student in the research lab! It''s a powerful thing to see them learn and grow into scientists over the course of a semester or two.LH: What motivated you to take on undergraduate research students at the start?Handelsman: I started undergraduate research myself in my first year of college—I walked into a lab and asked to do experiments. The difference between doing research and reading about it is so dramatic. I''ve always assumed that part of the structure of an academic lab is undergraduate involvement. Interestingly, I sometimes give the undergraduates riskier projects than the graduate students, who have more to lose if their projects fail.LH: Thanks for sharing your insights into teaching with CBE-LSE.     

Using Saccharomyces cerevisiae to test the mutagenicity of household compounds: an open ended hypothesis-driven teaching lab

In our Fundamentals of Genetics lab, students perform a wide variety of labs to reinforce and extend the topics covered in lecture. I developed an active-learning lab to augment the lecture topic of mutagenesis. In this lab exercise, students determine if a compound they bring from home is a mutagen. Students are required to read extensive background material, perform research to find a potential mutagen to test, develop a hypothesis, and bring to the lab their own suspected mutagen. This lab uses a specially developed strain of Saccharomyces cerevisiae, D7, to determine if a compound is a mutagen. Mutagenesis of the D7 genome can lead to a scorable alteration in the phenotypes of this strain. Students outline and carry out a protocol for treatment of the yeast tester strain, utilizing the concept of dose/response and positive and negative controls. Students report on their results using a PowerPoint presentation to simulate giving a scientific presentation. The students' self-assessment of their knowledge indicated that, in all cases, the students felt that they knew more about the assay, mutagenesis, and the relationship between genotype and phenotype (P < 0.05) after completing the exercise.     

Fostering students' knowledge and argumentation skills through dilemmas in human genetics

This study examined the outcomes of a unit that integrates explicit teaching of general reasoning patterns into the teaching of a specific science content. Specifically, this article examined the teaching of argumentation skills in the context of dilemmas in human genetics. Before instruction only a minority (16.2%) of the students referred to correct, specific biological knowledge in constructing arguments in the context of dilemmas in genetics. Approximately 90% of the students were successful in formulating simple arguments. An assessment that took place following instruction supported the conclusion that integrating explicit teaching of argumentation into the teaching of dilemmas in human genetics enhances performance in both biological knowledge and argumentation. An increase was found in the frequency of students who referred to correct, specific biological knowledge in constructing arguments. Students in the experimental group scored significantly higher than students in the comparison group in a test of genetics knowledge. An increase was also found in the quality of students' argumentation. Students were able to transfer the reasoning abilities taught in the context of genetics to the context of dilemmas taken from everyday life. The effects of metacognitive thinking and of changing students' thinking dispositions by modifying what is considered valuable in the class culture are discussed. © 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 35–62, 2002     

Post–Vision and Change: Do We Know How to Change?

The scale and importance of Vision and Change in Undergraduate Biology Education: A Call to Action challenges us to ask fundamental questions about widespread transformation of college biology instruction. I propose that we have clarified the “vision” but lack research-based models and evidence needed to guide the “change.” To support this claim, I focus on several key topics, including evidence about effective use of active-teaching pedagogy by typical faculty and whether certain programs improve students’ understanding of the Vision and Change core concepts. Program evaluation is especially problematic. While current education research and theory should inform evaluation, several prominent biology faculty–development programs continue to rely on self-reporting by faculty and students. Science, technology, engineering, and mathematics (STEM) faculty-development overviews can guide program design. Such studies highlight viewing faculty members as collaborators, embedding rewards faculty value, and characteristics of effective faculty-development learning communities. A recent National Research Council report on discipline-based STEM education research emphasizes the need for long-term faculty development and deep conceptual change in teaching and learning as the basis for genuine transformation of college instruction. Despite the progress evident in Vision and Change, forward momentum will likely be limited, because we lack evidence-based, reliable models for actually realizing the desired “change.”

All members of the biology academic community should be committed to creating, using, assessing, and disseminating effective practices in teaching and learning and in building a true community of scholars. (American Association for the Advancement of Science [AAAS], 2011 , p. 49)

Realizing the “vision” in Vision and Change in Undergraduate Biology Education (Vision and Change; AAAS, 2011 ) is an enormous undertaking for the biology education community, and the scale and critical importance of this challenge prompts us to ask fundamental questions about widespread transformation of college biology teaching and learning. For example, Vision and Change reflects the consensus that active teaching enhances the learning of biology. However, what is known about widespread application of effective active-teaching pedagogy and how it may differ across institutional and classroom settings or with the depth of pedagogical understanding a biology faculty member may have? More broadly, what is the research base concerning higher education biology faculty–development programs, especially designs that lead to real change in classroom teaching? Has the develop-and-disseminate approach favored by the National Science Foundation''s (NSF) Division of Undergraduate Education (Dancy and Henderson, 2007 ) been generally effective? Can we directly apply outcomes from faculty-development programs in other science, technology, engineering, and mathematics (STEM) disciplines or is teaching college biology unique in important ways? In other words, if we intend to use Vision and Change as the basis for widespread transformation of biology instruction, is there a good deal of scholarly literature about how to help faculty make the endorsed changes or is this research base lacking?In the context of Vision and Change, in this essay I focus on a few key topics relevant to broad-scale faculty development, highlighting the extent and quality of the research base for it. My intention is to reveal numerous issues that may well inhibit forward momentum toward real transformation of college-level biology teaching and learning. Some are quite fundamental, such as ongoing dependence on less reliable assessment approaches for professional-development programs and mixed success of active-learning pedagogy by broad populations of biology faculty. I also offer specific suggestions to improve and build on identified issues.At the center of my inquiry is the faculty member. Following the definition used by the Professional and Organizational Development Network in Higher Education (www.podnetwork.org), I use “faculty development” to indicate programs that emphasize the individual faculty member as teacher (e.g., his or her skill in the classroom), scholar/professional (publishing, college/university service), and person (time constraints, self-confidence). Of course, faculty members work within particular departments and institutions, and these environments are clearly critical as well (Stark et al., 2002 ). Consequently, in addition to focusing on the individual, faculty-development programs may also consider organizational structure (such as administrators and criteria for reappointment and tenure) and instructional development (the overall curriculum, who teaches particular courses). In fact, Diamond (2002) emphasizes that the three areas of effort (individual, organizational, instructional) should complement one another in faculty-development programs. The scope of the numerous factors impacting higher education biology instruction is a realistic reminder about the complexity and challenge of the second half of the Vision and Change endeavor.This essay is organized around specific topics meant to be representative and to illustrate the state of the art of widespread (beyond a limited number of courses and institutions) professional development for biology faculty. The first two sections focus on active teaching and biology students’ conceptual understanding, respectively. The third section concerns important elements that have been identified as critical for effective STEM faculty-development programs.     

“What if students revolt?”—Considering Student Resistance: Origins,Options, and Opportunities for Investigation

Instructors attempting new teaching methods may have concerns that students will resist nontraditional teaching methods. The authors provide an overview of research characterizing the nature of student resistance and exploring its origins. Additionally, they provide potential strategies for avoiding or addressing resistance and pose questions about resistance that may be ripe for research study.

“What if the students revolt?” “What if I ask them to talk to a neighbor, and they simply refuse?” “What if they do not see active learning as teaching?” “What if they just want me to lecture?” “What if my teaching evaluation scores plummet?” “Even if I am excited about innovative teaching and learning, what if I encounter student resistance?”

These are genuine concerns of committed and thoughtful instructors who aspire to respond to the repeated national calls to fundamentally change the way biology is taught in colleges and universities across the United States. No doubt most individuals involved in promoting innovative teaching in undergraduate biology education have heard these or variations on these fears and concerns. While some biology instructors may be at a point where they are still skeptical of innovative teaching from more theoretical perspectives (“Is it really any better than lecturing?”), the concerns expressed by the individuals above come from a deeply committed and practical place. These are instructors who have already passed the point where they have become dissatisfied with traditional teaching methods. They have already internally decided to try new approaches and have perhaps been learning new teaching techniques themselves. They are on the precipice of actually implementing formerly theoretical ideas in the real, messy space that is a classroom, with dozens, if not hundreds, of students watching them. Potential rejection by students as they are practicing these new pedagogical skills represents a real and significant roadblock. A change may be even more difficult for those earning high marks from their students for their lectures. If we were to think about a learning progression for faculty moving toward requiring more active class participation on the part of students, the voices above are from those individuals who are progressing along this continuum and who could easily become stuck or turn back in the face of student resistance.Unfortunately, it appears that little systematic attention or research effort has been focused on understanding the origins of student resistance in biology classrooms or the options for preventing and addressing such resistance. As always, this Feature aims to gather research evidence from a variety of fields to support innovations in undergraduate biology education. Below, we attempt to provide an overview of the types of student resistance one might encounter in a classroom, as well as share hypotheses from other disciplines about the potential origins of student resistance. In addition, we offer examples of classroom strategies that have been proposed as potentially useful for either preventing student resistance from happening altogether or addressing student resistance after it occurs, some of which align well with findings from research on the origins of student resistance. Finally, we explore how ready the field of student resistance may be for research study, particularly in undergraduate biology education.     

Understanding genetics: Analysis of secondary students' conceptual status

This article explores the conceptual change of students in Grades 10 and 12 in three Australian senior high schools when the teachers included computer multimedia to a greater or lesser extent in their teaching of a genetics course. The study, underpinned by a multidimensional conceptual‐change framework, used an interpretive approach and a case‐based design with multiple data collection methods. Over 4–8 weeks, the students learned genetics in classroom lessons that included BioLogica activities, which feature multiple representations. Results of the online tests and interview tasks revealed that most students improved their understanding of genetics as evidenced in the development of genetics reasoning. However, using Thorley's (1990) status analysis categories, a cross‐case analysis of the gene conceptions of 9 of the 26 students interviewed indicated that only 4 students' postinstructional conceptions were intelligible–plausible–fruitful. Students' conceptual change was consistent with classroom teaching and learning. Findings suggested that multiple representations supported conceptual understanding of genetics but not in all students. It was also shown that status can be a viable hallmark enabling researchers to identify students' conceptual change that would otherwise be less accessible. Thorley's method for analyzing conceptual status is discussed. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 205–235, 2007     

Immediate Dissemination of Student Discoveries to a Model Organism Database Enhances Classroom-Based Research Experiences

Use of inquiry-based research modules in the classroom has soared over recent years, largely in response to national calls for teaching that provides experience with scientific processes and methodologies. To increase the visibility of in-class studies among interested researchers and to strengthen their impact on student learning, we have extended the typical model of inquiry-based labs to include a means for targeted dissemination of student-generated discoveries. This initiative required: 1) creating a set of research-based lab activities with the potential to yield results that a particular scientific community would find useful and 2) developing a means for immediate sharing of student-generated results. Working toward these goals, we designed guides for course-based research aimed to fulfill the need for functional annotation of the Tetrahymena thermophila genome, and developed an interactive Web database that links directly to the official Tetrahymena Genome Database for immediate, targeted dissemination of student discoveries. This combination of research via the course modules and the opportunity for students to immediately “publish” their novel results on a Web database actively used by outside scientists culminated in a motivational tool that enhanced students’ efforts to engage the scientific process and pursue additional research opportunities beyond the course.     

Modeling Sources of Teaching Self-Efficacy for Science,Technology, Engineering,and Mathematics Graduate Teaching Assistants

Graduate teaching assistants (GTAs) in science, technology, engineering, and mathematics (STEM) have a large impact on undergraduate instruction but are often poorly prepared to teach. Teaching self-efficacy, an instructor’s belief in his or her ability to teach specific student populations a specific subject, is an important predictor of teaching skill and student achievement. A model of sources of teaching self-efficacy is developed from the GTA literature. This model indicates that teaching experience, departmental teaching climate (including peer and supervisor relationships), and GTA professional development (PD) can act as sources of teaching self-efficacy. The model is pilot tested with 128 GTAs from nine different STEM departments at a midsized research university. Structural equation modeling reveals that K–12 teaching experience, hours and perceived quality of GTA PD, and perception of the departmental facilitating environment are significant factors that explain 32% of the variance in the teaching self-efficacy of STEM GTAs. This model highlights the important contributions of the departmental environment and GTA PD in the development of teaching self-efficacy for STEM GTAs.Science, technology, engineering, and mathematics (STEM) graduate teaching assistants (GTAs) play a significant role in the learning environment of undergraduate students. They are heavily involved in the instruction of undergraduate students at master’s- and doctoral-granting universities (Nyquist et al., 1991 ; Johnson and McCarthy, 2000 ; Sundberg et al., 2005 ; Gardner and Jones, 2011 ). GTAs are commonly in charge of laboratory or recitation sections, in which they often have more contact and interaction with the students than the professor who is teaching the course (Abraham et al., 1997 ; Sundberg et al., 2005 ; Prieto and Scheel, 2008 ; Gardner and Jones, 2011 ).Despite the heavy reliance on GTAs for instruction and the large potential for them to influence student learning, there is evidence that many GTAs are completely unprepared or at best poorly prepared for their role as instructors (Abraham et al., 1997 ; Rushin et al., 1997 ; Shannon et al., 1998 ; Golde and Dore, 2001 ; Fagen and Wells, 2004 ; Luft et al., 2004 ; Sundberg et al., 2005 ; Prieto and Scheel, 2008 ). For example, in molecular biology, 71% of doctoral students are GTAs, but only 30% have had an opportunity to take a GTA professional development (PD) course that lasted at least one semester (Golde and Dore, 2001 ). GTAs often teach in a primarily directive manner and have intuitive notions about student learning, motivation, and abilities (Luft et al., 2004 ). For those who experience PD, university-wide PD is often too general (e.g., covering university policies and procedures, resources for students), and departmental PD does not address GTAs’ specific teaching needs; instead departmental PD repeats the university PD (Jones, 1993 ; Golde and Dore, 2001 ; Luft et al., 2004 ). Nor do graduate experiences prepare GTAs to become faculty and teach lecture courses (Golde and Dore, 2001 ).While there is ample evidence that many GTAs are poorly prepared, as well as studies of effective GTA PD programs (biology examples include Schussler et al., 2008 ; Miller et al., 2014 ; Wyse et al., 2014 ), the preparation of a graduate student as an instructor does not occur in a vacuum. GTAs are also integral members of their departments and are interacting with faculty and other GTAs in many different ways, including around teaching (Bomotti, 1994 ; Notarianni-Girard, 1999 ; Belnap, 2005 ; Calkins and Kelly, 2005 ). It is important to build good working relationships among the GTAs and between the GTAs and their supervisors (Gardner and Jones, 2011 ). However, there are few studies that examine the development of GTAs as integral members of their departments and determine how departmental teaching climate, GTA PD, and prior teaching experiences can impact GTAs.To guide our understanding of the development of GTAs as instructors, a theoretical framework is important. Social cognitive theory is a well-developed theoretical framework for describing behavior and can be applied specifically to teaching (Bandura, 1977 , 1986 , 1997 , 2001 ). A key concept in social cognitive theory is self-efficacy, which is a person’s belief in his or her ability to perform a specific task in a specific context (Bandura, 1997 ). High self-efficacy correlates with strong performance in a task such teaching (Bandura, 1997 ; Tschannen-Moran and Hoy, 2007 ). Teaching self-efficacy focuses on teachers’ perceptions of their ability to “organize and execute courses of action required to successfully accomplish a specific teaching task in a particular context” (Tschannen-Moran et al., 1998 , p. 233). High teaching self-efficacy has been shown to predict a variety of types of student achievement among K–12 teachers (Ashton and Webb, 1986 ; Anderson et al., 1988 ; Ross, 1992 ; Dellinger et al., 2008 ; Klassen et al., 2011 ). In GTAs, teaching self-efficacy has been shown to be related to persistence in academia (Elkins, 2005 ) and student achievement in mathematics (Johnson, 1998 ). High teaching self-efficacy is evidenced by classroom behaviors such as efficient classroom management, organization and planning, and enthusiasm (Guskey, 1984 ; Allinder, 1994 ; Dellinger et al., 2008 ). Instructors with high teaching self-efficacy work continually with students to help them in learning the material (Gibson and Dembo, 1984 ). These instructors are also willing to try a variety of teaching methods to improve their teaching (Stein and Wang, 1988 ; Allinder, 1994 ). Instructors with high teaching self-efficacy perform better as teachers, are persistent in difficult teaching tasks, and can positively affect their student’s achievement.These behaviors of successful instructors, which can contribute to student success, are important to foster in STEM GTAs. Understanding of what influences the development of teaching self-efficacy in STEM GTAs can be used to improve their teaching self-efficacy and ultimately their teaching. Therefore, it is important to understand what impacts teaching self-efficacy in STEM GTAs. Current research into factors that influence GTA teaching self-efficacy are generally limited to one or two factors in a study (Heppner, 1994 ; Prieto and Altmaier, 1994 ; Prieto and Meyers, 1999 ; Prieto et al., 2007 ; Liaw, 2004 ; Meyers et al., 2007 ). Studying these factors in isolation does not allow us to understand how they work together to influence GTA teaching self-efficacy. Additionally, most studies of GTA teaching self-efficacy are not conducted with STEM GTAs. STEM instructors teach in a different environment and with different responsibilities than instructors in the social sciences and liberal arts (Lindbloom-Ylanne et al., 2006 ). These differences could impact the development of teaching self-efficacy of STEM GTAs compared with social science and liberal arts GTAs. To further our understanding of the development of STEM GTA teaching self-efficacy, this paper aims to 1) describe a model of factors that could influence GTA teaching self-efficacy, and 2) pilot test the model using structural equation modeling (SEM) on data gathered from STEM GTAs. The model is developed from social cognitive theory and GTA teaching literature, with support from the K–12 teaching self-efficacy literature. This study is an essential first step in improving our understanding of the important factors impacting STEM GTA teaching self-efficacy, which can then be used to inform and support the preparation of effective STEM GTAs.     

Re: Misconceptions Are “So Yesterday!”

A response to Maskiewicz and Lineback''s essay in the September 2013 issue of CBE-Life Sciences Education.Dear Editor:Maskiewicz and Lineback (2013) have written a provocative essay about how the term misconceptions is used in biology education and the learning sciences in general. Their historical perspective highlights the logic and utility of the constructivist theory of learning. They emphasize that students’ preliminary ideas are resources to be built upon, not errors to be eradicated. Furthermore, Maskiewicz and Lineback argue that the term misconception has been largely abandoned by educational researchers, because it is not consistent with constructivist theory. Instead, they conclude, members of the biology education community should speak of preconceptions, naïve conceptions, commonsense conceptions, or alternative conceptions.We respectfully disagree. Our objections encompass both the semantics of the term misconception and the more general issue of constructivist theory and practice. We now address each of these in turn. (For additional discussion, please see Leonard, Andrews, and Kalinowski , “Misconceptions Yesterday, Today, and Tomorrow,” CBE—Life Sciences Education [LSE], in press, 2014.)Is misconception suitable for use in scholarly discussions? The answer depends partly on the intended audience. We avoid using the term misconception with students, because it could be perceived as pejorative. However, connotations of disapproval are less of a concern for the primary audience of LSE and similar journals, that is, learning scientists, discipline-based education researchers, and classroom teachers.An additional consideration is whether misconception is still used in learning sciences outside biology education. Maskiewicz and Lineback claim that misconception is rarely used in journals such as Cognition and Instruction, Journal of the Learning Sciences, Journal of Research in Science Teaching, and Science Education, yet the term appears in about a quarter of the articles published by these journals in 2013 (National Research Council, 2012 ).

Table 1.

Use of the term misconception in selected education research journals in 2013

The EvoDevoCI: A Concept Inventory for Gauging Students’ Understanding of Evolutionary Developmental Biology

The American Association for the Advancement of Science 2011 report Vision and Change in Undergraduate Biology Education encourages the teaching of developmental biology as an important part of teaching evolution. Recently, however, we found that biology majors often lack the developmental knowledge needed to understand evolutionary developmental biology, or “evo-devo.” To assist in efforts to improve evo-devo instruction among undergraduate biology majors, we designed a concept inventory (CI) for evolutionary developmental biology, the EvoDevoCI. The CI measures student understanding of six core evo-devo concepts using four scenarios and 11 multiple-choice items, all inspired by authentic scientific examples. Distracters were designed to represent the common conceptual difficulties students have with each evo-devo concept. The tool was validated by experts and administered at four institutions to 1191 students during preliminary (n = 652) and final (n = 539) field trials. We used student responses to evaluate the readability, difficulty, discriminability, validity, and reliability of the EvoDevoCI, which included items ranging in difficulty from 0.22–0.55 and in discriminability from 0.19–0.38. Such measures suggest the EvoDevoCI is an effective tool for assessing student understanding of evo-devo concepts and the prevalence of associated common conceptual difficulties among both novice and advanced undergraduate biology majors.