Secondary Students' Understanding of Genetics Using BioLogica: Two Case Studies

This chapter reexamines our research on secondary students’ understanding of genetics in terms of gene conceptions and reasoning when they learned genetics with multiple external representations (MERs). In our Australian study, teachers in three Perth schools included interactive BioLogica activities which feature manipulable MERs to varying degrees in their teaching. In our Hong Kong study, students used BioLogica in an after-school program for which the teacher and researcher provided bilingual support and both group and individual feedback. The results of our studies—from a cross-case analysis of students’ gene conceptions and genetics reasoning based on interviews, online two-tier tests, computer log files, and other data sources—indicated that most students improved their understanding of genetics to varying extent in terms of sophistication of their gene conceptions and the six types of genetics reasoning. The findings suggest that MERs supported understanding of genetics but not for all students. We compare the Australian and Hong Kong studies in terms of students’ genetics reasoning, explore how students learned complex content in biology using MERs within different learning contexts, and discuss the potential of visual-graphical and bilingual representations for scaffolding the learning of English language learner (ELL) students

Wilms' Tumor Protein Wt1 Is an Activator of the Anti-Müllerian Hormone Receptor Gene Amhr2

The Wilms' tumor protein Wt1 plays an essential role in mammalian urogenital development. WT1 mutations in humans lead to a variety of disorders, including Wilms' tumor, a pediatric kidney cancer, as well as Frasier and Denys-Drash syndromes. Phenotypic anomalies in Denys-Drash syndrome include pseudohermaphroditism and sex reversal in extreme cases. We have used cDNA microarray analyses on Wt1 knockout mice to identify Wt1-dependent genes involved in sexual development. The gene most dramatically affected by Wt1 inactivation was Amhr2, encoding the anti-Müllerian hormone (Amh) receptor 2. Amhr2 is an essential factor for the regression of the Müllerian duct in males, and mutations in AMHR2 lead to the persistent Müllerian duct syndrome, a rare form of male pseudohermaphroditism. Here we show that Wt1 and Amhr2 are coexpressed during urogenital development and that the Wt1 protein binds to the promoter region of the Amhr2 gene. Inactivation and overexpression of Wt1 in cell lines was followed by immediate changes of Amhr2 expression. The identification of Amhr2 as a Wt1 target provides new insights into the role of Wt1 in sexual differentiation and indicates, in addition to its function in early gonad development and sex determination, a novel function for Wt1, namely, in Müllerian duct regression

Introducing Pre-university Students to Primary Scientific Literature Through Argumentation Analysis

<p>Primary scientific literature is one of the most important means of communication in science, written for peers in the scientific community. Primary literature provides an authentic context for showing students how scientists support their claims. Several teaching strategies have been proposed using (adapted) scientific publications, some for secondary education, but none of these strategies focused specifically on scientific argumentation. The purpose of this study is to evaluate a strategy for teaching pre-university students to read unadapted primary scientific literature, translated into students' native language, based on a new argumentation analysis framework. This framework encompasses seven types of argumentative elements: motive, objective, main conclusion, implication, support, counterargument and refutation. During the intervention, students studied two research articles. We monitored students' reading comprehension and their opinion on the articles and activities. After the intervention, we measured students' ability to identify the argumentative elements in a third unadapted and translated research article. The presented framework enabled students to analyse the article by identifying the motive, objective, main conclusion and implication and part of the supports. Students stated that they found these activities useful. Most students understood the text on paragraph level and were able to read the article with some help for its vocabulary. We suggest that primary scientific literature has the potential to show students important aspects of the scientific process and to learn scientific vocabulary in an authentic context.</p>