learn the functions of the frog skin to protection from predation through camouflage and secretion of poison. The problems of dissection are: some students responded primarily with anxiety and dread, virtually all of the students felt at least somewhat negative, hesitant, uncomfortable or ambivalent toward the prospect of dissecting. Even those eager to dissect often described conflicted feelings. By far, the most common problem for students was squeamishness. Nearly every student reported feelings of disgust when they thought about the impending dissection. In many cases, students openly admitted that they or others in the class thought that dissection was “gross,” “sick” or “disgusting”. Students feel uncomfortable because they are making physical contact with animals in ways they would usually define as inappropriate. Dissection can create negative attitudes towards animal as well as creating psychological trauma in students. According to Orlans (1988), when dissection was first introduced some students lost their interest in biology due to the negative feelings and psychological trauma evoked by dissection classes. The National Association of Biology Teachers (NABT) (1990) supports the use of interactive videodiscs and computer simulation as alternatives to hands-on dissection wherever necessary. The National Anti-Vivisection Society (NAVS) (1997) claimed that the use of simulations in dissection would create compassion in student attitudes toward animal life. A related issue is whether dissection is gender biased. Science educators are becoming increasingly concerned about gender differences with respect to expectations, types of experiences and participation in science classrooms. Some might argue that males are more likely than females to enjoy dissection. From this viewpoint, requiring dissection in biology classes contributes to a male oriented dominance in science and contributes to gender inequities in science careers. Some gender differences in attitudes toward dissection were present. There are alternative methods of dissection, i.e., (a) models, mannequins, and mechanical simulators; (b) films and interactive videos; (c) computer simulations and virtual reality systems; (d) self-experimentation and human studies; (e) plant experiments; (f) observational and field studies, (g) waste materials from slaughterhouses and fisheries; (h) in vitro studies on cell lines; (h) and dead animals from a humane and ethical source (for example, animals which have died naturally or which have been killed humanely after scientific procedures). Computer simulation covers all of the standards, grasp students’ interests, and provide useful information that students can take with them on their journeys through college, into their careers, and ultimately on their quests to mature into well-informed contributors to society. Computer simulations provide the following: (a) provide comprehensive pre-dissection information on the anatomy and morphology of frog parts; (b) clarify unanswered questions that sometimes arise during dissections and to provide interactive, in-depth lab experience on the physiology of amphibians; (c) the program was similar to traditional curriculum that emphasizes identification of anatomical structures and functions of frog organs; (d) most importantly, the program operates on the Macintosh computer which is available in nearly all the middle school
science laboratories. When students worked on the software, they were given a worksheet for key words and definitions to complete. Computer simulated instruction gives students the opportunity to observe a ‘‘real’’ world experience and interact with it. Pedagogical simulations can be used in teaching students the anatomy and morphology of complex organisms or understanding complex relations of animal parts and their basic functions without actually dissecting real animals. Advantages of alternatives depend on the learning objectives. Animal-free models have several advantages over animal experiments. In cases where students are not well prepared for work with animals, the emotions aroused by being confronted with a dead or live animal might detract from the actual learning experience. Non-animal models can be developed in such a way as to achieve the learning objectives more effectively. For example: (a) a specific animal experiment might only be offered once, whereas an alternative model can often be used repeatedly without constraints on time and place of study; (b) alternative models can offer unambiguous and complete data, and can avoid the negative learning experience of an unsuccessful experiment; (c) an alternative can have built-in self-assessment to allow students to gauge whether staged learning objectives have been achieved; and (d) alternatives which make use of modern audio-visual techniques offer the possibility of demonstrating phenomena that are normally unobservable in the equivalent animal experiment, such as animations of organ and cell functions and flythrough of organ systems. Although in some cases the development of an alternative model can be expensive, it could be used repeatedly. Overall, the alternative model is cheaper than purchasing and caring for large groups of animals. The use of an alternative can also often save time for both the teacher and the students. Ultimately, in some situations, virtual biology learning experiences may be better than the hands on learning experience. The visual images and videos are more realistic. Videos followed in order of preference by class debates, discussions, lectures, work groups, printed matter and questions and answers. In a survey, 80 biology teachers from different districts of West Bengal provided their opinion. The participants ranged in age from 24 to 58 years old. These teachers had some prior experience in animal dissection, but had no experience in computer-simulated interactive dissection. Eight-seven percent of teachers give there opinion in favor of anti-dissection teaching. From the above answers, we can conclude that (animal) frog dissection is not an essential part of knowledge construction. There are now so many alternative methods of dissection, which are equally or sometimes more efficient in teaching students, that actual dissection is no longer necessary. In situations where real animal dissections are required, we should first provide a virtual lesson that covers all goals of the lesson plan. After the virtual dissection is, completed students can then dissect the physical animal if desired. In this case, the knowledge gained from the virtual lesson brings more meaning and understanding when dissecting the physical frog. References 1.
F. B. Orlans, Am. Biol. Teach. 50, 6 (1988).
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