What is alive? Students' conceptions of the traits that unite living organisms

Biology is the study of life, but students often hold misconceptions about what it means to be alive, with children often associating life with movement. These misconceptions can lead to biases in what students think is alive, with younger children often not thinking of plants as living given their lack of discernable movement. Despite this past work, there have been no prior studies that we are aware of that have examined how students in introductory biology conceptualize what it means to be alive. Here, we draw upon a fortuitous dataset collected from an in-class activity done on the first day of introductory biology courses at a two-year college and four-year university in close proximity to characterize how students in these classes think of life prior to instruction in the course. Our results indicate that there is widespread variation in how students think of life, with only one theme - reproduction - found in a majority of students' responses. Despite this variation, we find that many students recognize criteria for life that align with criteria commonly cited in the scientific literature. However, there remain discrepancies in students' thinking versus how the scientific community and introductory biology textbooks describe what it means to be alive, with students continuing to hold some misconceptions. We conclude with implications for instructors for promoting student understanding on what it means to be alive.