What Undergraduates in Biology Don\u27t Know About Plant Structure and Growth

We were interested to know what undergraduates in biology understand about plant structure and growth, and in particular what misconceptions they hold. To date, there has been no comprehensive analysis of what college undergraduates know about this topic, so we designed a study to address this deficiency. Students at two liberal arts colleges, two mid-sized universities (both public and private) and one research university were interviewed one-on-one. They were asked a series of open-ended questions addressing how plants grow taller, grow in diameter, move water and organics, produce leaves, etc. All students had at least one semester of either introductory college biology or introductory plant biology, and most had two. In our preliminary analysis of responses, we see the following trends. The most frequent misconception is that herbaceous tissues are supported entirely by cell walls; the role of water pressure is not comprehended. For some topics, students lack knowledge so completely that they do not even have misconceptions to hold. The mechanism of phloem transport, bark formation and fertilization are in this category. About a third of the interviewees did not know how plants increase in diameter, how leaves form, or how lateral roots form. We have collected data on the specific coursework completed by each student and will also report on correlations between knowledge levels, misconceptions and academic training. Our results should be of use to instructors of both introductory biology and introductory plant biology, as instructors can be more effective if they plan specific learning activities to address misconceptions or topics where student retention of knowledge is poor