Reasoning about genetic mechanisms: Affordances and constraints for learning

Abstract

Mechanisms are central in scientific explanations. However, developing mechanistic explanations is difficult for students especially in domains in which mechanisms involve abstract components and functions, such as genetics. One of the core components of genetic mechanisms are proteins and their functions. Students struggle to reason about the role of proteins while learning genetics and show limited ability to provide mechanistic explanations of genetic phenomena. In genetics education there are currently two competing theoretical frameworks regarding what domain‐specific knowledge about proteins is important for reasoning about genetic mechanisms. One framework assumes knowledge about specific protein functions in the body, a tool kit of functions; the other framework assumes more abstracted knowledge about protein interactions that are common to all protein functions. These frameworks implicate different instructional frameworks: One offers to provide concrete examples of protein functions while the other offers a more general description of protein activity. Our aim in this study was to ascertain the ways in which students' reasoning about proteins' role in genetic phenomena (both familiar and novel) relates to the two theoretical frameworks. Toward this end we engaged 7th grade students in learning about proteins functions in the mechanisms underlying genetic traits using an online simulation environment that embodied key aspects of both frameworks. We analyzed students' responses to the final test questions in which they were asked to generatively reason about the underlying mechanisms of two novel genetic traits. Our findings suggest that students use proteins in their explanations mainly when they can explain the protein function and that knowledge about a few specific functions is insufficient to support conceptualization of new functions. Moreover, knowledge of general protein activities common to most functions is also insufficient. We suggest a new combined approach to supporting students' understanding of proteins' role in genetic mechanisms.

Students’ Understanding of the Dynamic Nature of Genetics: Characterizing Undergraduates’ Explanations for Interaction between Genetics and Environment

“…This suggests that knowledge about proteins may be useful for reasoning about mechanisms of phenotypic plasticity. This is in line with growing evidence over the past decade stressing the importance of learning about protein functions in order to support reasoning about a wide variety of genetic phenomena (e.g., Duncan et al, 2011;Todd and Kenyon, 2016;Todd et al, 2019;van Mil et al, 2016;Haskel-Ittah and Yarden, 2017;Haskel-Ittah et al, 2019). Additionally, we found that students also invoked ideas about regulation of gene expression and that such ideas were useful in fleshing out explanations about short-and long-term phenotypic plasticity changes.…”

“…Based on our own prior work, we propose that these decisions depend on domain-specific knowledge of appropriate entities (and their activities) in the domain (Duncan, 2007;Haskel-Ittah et al, 2019). For example, when we asked seventh-grade students to explain the effect of genes on certain traits, they used the entity "protein" only in cases in which they knew of a relevant protein activity that could account for the formation of the trait in question.…”

It takes two to tango: How scientific reasoning and self-regulation processes impact argumentation quality

“…Students have issues with understanding the relationship between genes and observed traits and more specifically how the synthesized proteins are involved in the expression of traits (Thörne & Gericke, 2014). The ability to reason about genetic principles is important for general scientific literacy, for example, to understand genetically modified organisms (Haskel-Ittah et al, 2019).…”

Factor and Rasch Analysis on COVID-19 Genetics Literacy Assessment Instrument

“…Although proteins are not genetic material, they are involved as components that regulate the genetic expression of many genes. However, many students have difficulty understanding the involvement of proteins in trait determination mechanisms (Haskel-Ittah & Yarden, 2017;Haskel-Ittah et al, 2020;Thörne et al, 2013). Therefore, to ensure and evaluate student literacy more thoroughly, this concept also needs to be accessed.…”