Investigating Novice and Expert Conceptions of Genetically Modified Organisms

Abstract

The aspiration of biology education is to give students tools to apply knowledge learned in the classroom to everyday life. Genetic modification is a real-world biological concept that relies on an in-depth understanding of the molecular behavior of DNA and proteins. This study investigated undergraduate biology students' conceptions of genetically modified organisms (GMOs) when probed with real-world, molecular and cellular, and essentialist cues, and how those conceptions compared across biology expertise. We developed a novel written assessment tool and administered it to 120 non-biology majors, 154 entering biology majors, 120 advanced biology majors (ABM), and nine biology faculty. Results indicated that undergraduate biology majors rarely included molecular and cellular rationales in their initial explanations of GMOs. Despite ABM demonstrating that they have much of the biology knowledge necessary to understand genetic modification, they did not appear to apply this knowledge to explaining GMOs. Further, this study showed that all undergraduate student populations exhibited evidence of essentialist thinking while explaining GMOs, regardless of their level of biology training. Finally, our results suggest an association between scientifically accurate ideas and the application of molecular and cellular rationales, as well as an association between misconceptions and essentialist rationales.

FIGURE 1.

Molecular rationales included in participants’ open-ended written responses to the following assessment items: (A) “How would you explain to a professional colleague what a GMO is?” The comparison between ABM and faculty is significant to p < 0.0001 (Pearson chi-square test). (B) “How would you explain to a professional colleague what the relationship is between DNA and traits?” The comparison between EBM and ABM is significant to p < 0.0001 (Pearson chi-square test). †, Comparison between ABM responses in A and B. (C) “The genetically modified corn’s DNA is toxic to the insect pest that eats the corn.” The comparison between ABM and faculty is significant to p < 0.001 (Pearson chi-square test). ††, Comparison between ABM responses in B and C. The dashed line represents the percentage of ABM who gave molecular rationales in A, and the dotted line represents the percentage of ABM who gave molecular rationales in B. Both are displayed for ease of comparison. Pearson chi-square test: 
**, p < 0.001; ***, p < 0.0001.

FIGURE 2.

Participants’ responses to molecular and cellular assessment prompt 4: “The genetically modified corn’s DNA is toxic to the insect pest that eats the corn.” (A) Closed-ended scale: disagree (scientifically accurate; dotted), agree (scientifically inaccurate; striped), don’t know (gray). The difference between ABM and faculty in the percentage of people who responded “disagree” was significant to p < 0.001 (Pearson chi-square test). The difference between ABM and faculty in the percentage of people who responded “agree” was significant to p < 0.005 (Pearson chi-square test). (B) Participants who included molecular and cellular rationales in open-ended responses (black) were significantly more likely to disagree (the scientifically accurate response) than to agree. All comparisons significant to p < 0.0001.

FIGURE 3.

Participants’ responses to essentialist assessment prompt 5: “I consider this genetically modified corn with a bacterial gene to be…” (A) Closed-ended scale: a variety of corn (scientifically accurate; dotted; †, comparison between EBM and ABM; ††, comparison between ABM and faculty), a hybrid of corn and bacteria (essentialist; striped; †††, comparison between EBM and ABM), neither corn nor bacteria (dark gray), or a variety of bacteria (light gray). (B) Of the participants who chose “a variety of corn,” those who included a molecular and cellular rationale (black). (C) Of the participants who chose “a hybrid of corn and bacteria,” those who included an essentialist rationale (zigzag pattern). Pearson chi-square test: **, p < 0.001; ***, p < 0.0001.

FIGURE 4.

Participants’ responses to essentialist assessment prompt 6: “The bacterial DNA is present in the cells of all the parts of the genetically modified corn.” (A) Closed-ended scale: agree (scientifically accurate; striped), disagree (essentialist; dotted), don’t know (dark gray). (B) Participants who included a molecular and cellular rationale (black) were significantly more likely to agree (which is scientifically accurate) than to disagree (Pearson chi-square test: p < 0.0001). (C) Participants who included an essentialist rationale (zigzag pattern) were significantly more likely to disagree (which is scientifically inaccurate) than to agree (Pearson chi-square test: p < 0.0001).