A New Twist on DNA Extraction

Autor/inn/en	Chowning, Jeanne Ting; Wu, Regina; Brinkema, Caren; Crocker, Wendy; Bass, Krystal; LaZerte, Debbie
Titel	A New Twist on DNA Extraction
Quelle	In: Science Teacher, 86 (2019) 6, S.20-27 (8 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0036-8555
Schlagwörter	Genetics; Science Laboratories; Science Teachers; Persuasive Discourse; High School Students; Secondary School Teachers; Secondary School Science; Science Instruction; Science Activities + Suchen Sie Ihr Suchwort? Humangenetik; Science; Teacher; Teachers; Science teacher; Wissenschaft; Lehrer; Lehrerin; Lehrende; Persuasion; Persuasive Kommunikation; High school; High schools; Student; Students; Oberschule; Schüler; Schülerin; Studentin; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht
Abstract	DNA extraction from strawberries is a well-known procedure that allows students to visualize DNA and to recognize that living things contain DNA (NHGRI 2018, Science Buddies 2013). In this article, the authors describe a modification to the traditional DNA extraction protocol that promotes student agency in experimental design and also emphasizes important social dimensions of argumentation. The lesson provides ample opportunities for students to engage deeply in the social dimensions of argumentation. First, small groups of students design their own DNA extraction protocols based on their knowledge of cell structure and the properties of biomolecules. Within each group, they collaborate to make claims about a procedure that they expect to be effective, providing reasoning for using certain materials in a certain order. After obtaining their results, they conduct a "lab meeting," in which each group presents its protocol, the rationale for its design decisions, and its results. Students engage in questioning and critiquing the approaches of others as they try to build a collective understanding of the most effective approaches. The lab meeting introduces a critical aspect of scientific argumentation, one that is often neglected in school settings: collaborative discussion, critique, and sense-making about procedures. This approach allows teachers to emphasize the central role of collaborative talk in science, as well as the social dimensions of scientific argumentation as students puzzle out the best procedures for repeating the experiment. Structures such as lab meetings help provide students with insight into the roles of argumentation and sense-making in professional scientific communities. (ERIC).
Anmerkungen	National Science Teachers Association. 1840 Wilson Boulevard, Arlington, VA 22201-3000. Tel: 800-722-6782; Fax: 703-243-3924; e-mail: membership@nsta.org; Web site: http://www.nsta.org
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01