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1.
Basic phylogenetics and associated “tree thinking” are often minimized or excluded in formal school curricula. Informal settings provide an opportunity to extend the K–12 school curriculum, introducing learners to new ideas, piquing interest in science, and fostering scientific literacy. Similarly, university researchers participating in science, technology, engineering, and mathematics (STEM) outreach activities increase awareness of college and career options and highlight interdisciplinary fields of science research and augment the science curriculum. To aid in this effort, we designed a 6-h module in which students utilized 12 flowering plant species to generate morphological and molecular phylogenies using biological techniques and bioinformatics tools. The phylogenetics module was implemented with 83 high school students during a weeklong university STEM immersion program and aimed to increase student understanding of phylogenetics and coevolution of plants and pollinators. Student response reflected positive engagement and learning gains as evidenced through content assessments, program evaluation surveys, and program artifacts. We present the results of the first year of implementation and discuss modifications for future use in our immersion programs as well as in multiple course settings at the high school and undergraduate levels.
Just as beginning students in geography need to be taught how to read maps, so beginning students in biology should be taught how to read trees and to understand what trees communicate. O’Hara (1997 , p. 327)
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2.
Most American colleges and universities offer gateway biology courses to meet the needs of three undergraduate audiences: biology and related science majors, many of whom will become biomedical researchers; premedical students meeting medical school requirements and preparing for the Medical College Admissions Test (MCAT); and students completing general education (GE) graduation requirements. Biology textbooks for these three audiences present a topic scope and sequence that correlates with the topic scope and importance ratings of the biology content specifications for the MCAT regardless of the intended audience. Texts for “nonmajors,” GE courses appear derived directly from their publisher''s majors text. Topic scope and sequence of GE texts reflect those of “their” majors text and, indirectly, the MCAT. MCAT term density of GE texts equals or exceeds that of their corresponding majors text. Most American universities require a GE curriculum to promote a core level of academic understanding among their graduates. This includes civic scientific literacy, recognized as an essential competence for the development of public policies in an increasingly scientific and technological world. Deriving GE biology and related science texts from majors texts designed to meet very different learning objectives may defeat the scientific literacy goals of most schools’ GE curricula.  相似文献   

3.
This study investigates the influence of hands-on activities on students’ interest. We researched whether students with experience in specific hands-on activities show higher interest in these activities than students without experience. Furthermore, the relationship between the quality of the hands-on experience and interest in the respective activity was examined. In total, 28 typical hands-on activities of biology education were considered. The activities were divided into the categories experimentation, dissection, work with microscopes, and classification. A total of 141 students from the 11th grade completed questionnaires on interest in the hands-on activities, their experience with each activity, and the quality of the respective experience. Students’ interest in experimenting, working with microscopes, dissecting and classifying tends to benefit from performing hands-on activities. However, findings indicated that the performance of various hands-on activities can influence students’ interest differently. For seven hands-on activities, we identified a positive effect of hands-on experience on interest, while in one case, practical work appeared to have influenced students’ interest negatively. However, for most hands-on activities, no effect of experience on interest was found. The quality of hands-on experiences showed positive correlations with interest in the respective hands-on activities. Therefore, this paper argues in favour of designing biology lessons that allow for experiences with hands-on activities that also interest students. Our findings underline the necessity of investigating the effects of various hands-on activities in a differentiated manner.  相似文献   

4.
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.  相似文献   

5.
Phylogenetic trees provide visual representations of ancestor–descendant relationships, a core concept of evolutionary theory. We introduced “tree thinking” into our introductory organismal biology course (freshman/sophomore majors) to help teach organismal diversity within an evolutionary framework. Our instructional strategy consisted of designing and implementing a set of experiences to help students learn to read, interpret, and manipulate phylogenetic trees, with a particular emphasis on using data to evaluate alternative phylogenetic hypotheses (trees). To assess the outcomes of these learning experiences, we designed and implemented a Phylogeny Assessment Tool (PhAT), an open-ended response instrument that asked students to: 1) map characters on phylogenetic trees; 2) apply an objective criterion to decide which of two trees (alternative hypotheses) is “better”; and 3) demonstrate understanding of phylogenetic trees as depictions of ancestor–descendant relationships. A pre–post test design was used with the PhAT to collect data from students in two consecutive Fall semesters. Students in both semesters made significant gains in their abilities to map characters onto phylogenetic trees and to choose between two alternative hypotheses of relationship (trees) by applying the principle of parsimony (Occam''s razor). However, learning gains were much lower in the area of student interpretation of phylogenetic trees as representations of ancestor–descendant relationships.  相似文献   

6.
Implementing biotechnology education through hands-on teaching methods should be considered by secondary biology teachers. This study is an experimental research design to examine increased student content knowledge in biotechnology after a hands-on biotechnology intervention. The teachers from both school groups participated in, Project Crawfish, a biotechnology professional development program. Students from both schools completed a pre and post assessment. The classroom was the unit of analysis. When the assessment was analyzed, each school had statistically significant increases in student content knowledge (p < 0.0001 for the intervention school and p = 0.0481 for the control school). When the schools were compared to each other, a p-value of 0.0543 provided a suggestive relationship that the biotechnology intervention school had a larger increase in student content knowledge overall. When the assessment was divided into the five components, the intervention school showed significant increases in all five components. The control school had significant increases in student content knowledge in the PCR and DNA sequencing components (p = 0.0459, p = 0.0043, respectively).  相似文献   

7.
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 4L 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 4L 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.  相似文献   

8.
At the Universidad de Caldas, Manizales, Colombia, we used their new computer facilities to introduce chemistry graduate students to biochemical database mining and quantum chemistry calculations using freeware. These hands-on workshops allowed the students a strong introduction to easily accessible software and how to use this software to begin to explore computer modeling. Each workshop was scheduled for 2 h and each included a tutorial exercise to familiarize the students with the main menus and features of the software. In addition, accompanying lectures and practical laboratory sections were provided. Both courses were taught in Spanish although the written instructions were in English. This was not a problem since these students have a comfort level with reading English. Student feedback following these workshops was highly enthusiastic and positive. This international collaborative will impact both the teaching and research goals for this cohort of graduate students.  相似文献   

9.
Laboratory and demonstration have long been used to supplement lecture in chemistry education. Current research indicates that students are better served by laboratories which exercise the higher-order cognitive skills, such as inquiry-based laboratories. However, the time and the resources available to perform these recommended types of laboratories are continually shrinking. Due to these factors, a demonstration-laboratory was designed to allow students to make observations through demonstration rather then through hands-on laboratory. For this study, the hands-on procedures of an inquiry style laboratory were replaced by an instructor demonstration of these same procedures. A significant difference was found between student conceptual understanding before and after the experiment, indicating that students performing the laboratory experiment and students viewing the demonstration-laboratory had an increase in conceptual understanding. However, no significant difference was found between the conceptual understanding of the two groups after the experiment, indicating that students learn roughly the same from both methods and that the demonstration-laboratory at least does no harm to the students conceptually. Long-term effects on student understanding were not measured. Student opinions comparing the demonstration laboratory to a hands-on laboratory were also collected and analyzed.  相似文献   

10.
Colorful PowerPoint presentations with detailed drawings, micrographs, and short animations have become the standard format for illustrating the fundamental features of cell biology in large introductory classes. In this essay, we describe a low-tech tool that can be included in a standard lecture to help students visualize, understand, and remember the dynamic aspects of microscopic cell biological processes. This approach involves use of common objects, including pipe insulation and a garden hose, to illustrate basic processes such as protein folding and cloning, hence the appellation “garage demos.” The demonstrations are short, minimizing displacement of course content, easy to make, and provide an avenue for increasing student–faculty interaction in a large lecture hall. Student feedback over the past 4 years has been overwhelmingly positive. In an anonymous postclass survey in 2007, 90% of the respondents rated garage demos as having been very or somewhat helpful for understanding course concepts. Direct measurements of learning gains on specific concepts illustrated by garage demos are the focus of an ongoing study.  相似文献   

11.
A variance analysis of the relation between the amount of time students spent experiencing hands-on science and science achievement was performed. Data collected by the National Education Longitudinal Study of 1988 on a nationally representative sample of eighth-grade students were analyzed. Student achievement in science was measured by a cognitive test battery developed by the Educational Testing Service. Information regarding the frequency of hands-on experience was collected through a self-administered teacher questionnaire, which included a series of questions specific to the science curriculum. From the analysis it was concluded that significant differences existed across the hands-on frequency variable with respect to science achievement. Specifically, students who engaged in hands-on activities every day or once a week scored significantly higher on a standardized test of science achievement than students who engaged in hands-on activities once a month, less than once a month, or never. © 1996 John Wiley & Sons, Inc.  相似文献   

12.
Traditional courses for graduate students in the biological sciences typically span a semester, are organized around the fundamental concepts of a single discipline, and are aimed at the needs of incoming students. Such courses demand significant time commitment from both faculty and course participants; thus, they are avoided by a subset of the academic science community. Course length and the high barrier to course development are inhibitory to the creation of new courses, especially in emerging areas of biology that may not merit a full-semester approach. Here, we describe the implementation of a new, graduate-level course format, created to allow for rapid development of courses, provide meaningful educational experiences for both junior and senior graduate students and other members of our community, and increase the breadth of faculty involvement in teaching. These courses are greatly abbreviated, and thus termed “nanocourses.” Based on experience from the first three semesters, nanocourses seem to accomplish the initial goals that we set. Importantly, nanocourses engaged students, postdoctoral fellows, faculty, and others, thus providing a new mechanism to educate our community in response to rapid advances in biology. In our view, nanocourses are a useful tool that can supplement graduate-level curricula in varied ways.  相似文献   

13.
Molecular life science is one of the fastest-growing fields of scientific and technical innovation, and biotechnology has profound effects on many aspects of daily life—often with deep, ethical dimensions. At the same time, the content is inherently complex, highly abstract, and deeply rooted in diverse disciplines ranging from “pure sciences,” such as math, chemistry, and physics, through “applied sciences,” such as medicine and agriculture, to subjects that are traditionally within the remit of humanities, notably philosophy and ethics. Together, these features pose diverse, important, and exciting challenges for tomorrow''s teachers and educational establishments. With backgrounds in molecular life science research and secondary life science teaching, we (Tibell and Rundgren, respectively) bring different experiences, perspectives, concerns, and awareness of these issues. Taking the nature of the discipline as a starting point, we highlight important facets of molecular life science that are both characteristic of the domain and challenging for learning and education. Of these challenges, we focus most detail on content, reasoning difficulties, and communication issues. We also discuss implications for education research and teaching in the molecular life sciences.  相似文献   

14.
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.  相似文献   

15.
The Biology Intensive Orientation for Students (BIOS) Program was designed to assess the impact of a 5-d intensive prefreshman program on success and retention of biological science majors at Louisiana State University. The 2005 pilot program combined content lectures and examinations for BIOL 1201, Introductory Biology for Science Majors, as well as learning styles assessments and informational sessions to provide the students with a preview of the requirements of biology and the pace of college. Students were tracked after their BIOS participation, and their progress was compared with a control group composed of students on the BIOS waiting list and a group of BIOL 1201 students who were identified as the academic matches to the BIOS participants (high school GPA, ACT score, and gender). The BIOS participants performed significantly better on the first and second exams, they had a higher course average, and they had a higher final grade than the control group. These students also had higher success rates (grade of “A,” “B,” or “C”) during both the fall and spring semesters and remained on track through the first semester of their sophomore year to graduate in 4 yr at a significantly higher rate than the control group.  相似文献   

16.
One goal of postsecondary education is to assist students in developing expert-level understanding. Previous attempts to encourage expert-level understanding of phylogenetic analysis in college science classrooms have largely focused on isolated, or “one-shot,” in-class activities. Using a deliberate practice instructional approach, we designed a set of five assignments for a 300-level plant systematics course that incrementally introduces the concepts and skills used in phylogenetic analysis. In our assignments, students learned the process of constructing phylogenetic trees through a series of increasingly difficult tasks; thus, skill development served as a framework for building content knowledge. We present results from 5 yr of final exam scores, pre- and postconcept assessments, and student surveys to assess the impact of our new pedagogical materials on student performance related to constructing and interpreting phylogenetic trees. Students improved in their ability to interpret relationships within trees and improved in several aspects related to between-tree comparisons and tree construction skills. Student feedback indicated that most students believed our approach prepared them to engage in tree construction and gave them confidence in their abilities. Overall, our data confirm that instructional approaches implementing deliberate practice address student misconceptions, improve student experiences, and foster deeper understanding of difficult scientific concepts.  相似文献   

17.
Laboratory classes are commonplace and essential in biology departments but can sometimes be cumbersome, unreliable, and a drain on time and resources. As university intakes increase, pressure on budgets and staff time can often lead to reduction in practical class provision. Frequently, the ability to use laboratory equipment, mix solutions, and manipulate test animals are essential learning outcomes, and “wet” laboratory classes are thus appropriate. In others, however, interpretation and manipulation of the data are the primary learning outcomes, and here, computer-based simulations can provide a cheaper, easier, and less time- and labor-intensive alternative. We report the evaluation of two computer-based simulations of practical exercises: the first in chromosome analysis, the second in bioinformatics. Simulations can provide significant time savings to students (by a factor of four in our first case study) without affecting learning, as measured by performance in assessment. Moreover, under certain circumstances, performance can be improved by the use of simulations (by 7% in our second case study). We concluded that the introduction of these simulations can significantly enhance student learning where consideration of the learning outcomes indicates that it might be appropriate. In addition, they can offer significant benefits to teaching staff.  相似文献   

18.
In-depth interviews were conducted with 16 men who had a significant other who had given birth within the last 5 years. Men were asked about their perceptions of pregnancy-related weight gain, and content analysis was used to identify themes from the interviews. Men described nine themes related to perinatal weight gain: (a) negative perceptions, (b) eating behaviors, (c) exercise habits, (d) health impact, (e) body changes, (f) weight-loss success, (g) “it bothered her more than me,” (h) “the weight gain wasn’t a problem,” and (i) intimacy. Together, these themes offer a glimpse into men’s experiences and highlight the discord and balance between experiencing negative feelings/perceptions and being a supportive partner. This information on how men perceive pregnancy-related weight gain can be used to develop interventions to assist men to support their significant others in meeting weight loss goals following pregnancy.  相似文献   

19.
Research suggests that undergraduate students learn more from lab experiences that involve longer-term projects. We have developed a one-semester laboratory sequence aimed at sophomore-level undergraduates. In designing this curriculum, we focused on several educational objectives: 1) giving students a feel for the scientific research process, 2) introducing them to commonly used lab techniques, and 3) building skills in both data analysis and scientific writing. Over the course of the semester, students carry out two project-based lab experiences and write two substantial lab reports modeled on primary literature. Student assessment data indicate that this lab curriculum achieved these objectives. This article describes the first of these projects, which uses the biflagellate alga Chlamydomonas reinhardtii to introduce students to the study of flagellar motility, protein synthesis, microtubule polymerization, organelle assembly, and protein isolation and characterization.  相似文献   

20.
A lecture section of introductory biology that historically enrolled more than 500 students was split into two smaller sections of approximately 250 students each. A traditional lecture format was followed in the “traditional” section; lecture time in the “active” section was drastically reduced in favor of a variety of in-class student-centered activities. Students in both sections took unannounced quizzes and multiple-choice exams. Evaluation consisted of comparisons of student survey responses, scores on standardized teaching evaluation forms, section averages and attendance, and open-ended student comments on end-of-term surveys. Results demonstrate that students perform as well, if not better, in an active versus traditional environment. However, student concerns about instructor expectations indicate that a judicious balance of student-centered activities and presentation-style instruction may be the best approach.  相似文献   

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