As instructors of introductory biology courses for majors and non-majors, we have struggled with teaching the concept of cell structure and function in an engaging way.  However, this is a foundational concept that most biology instructors would agree is vital for all students to know. The overall objective of this teachable unit is to help non-major introductory biology students learn the names and functions of the basic components of eukaryotic cells and, at the same time, understand the connection between cellular structure and function using active learning approaches. The key component of this teachable unit is a group exercise termed Cell Engineer/Detective. In this exercise, students work in groups to design a cell that is well suited for a function that is provided to them by the instructor (Cell Engineer). The groups then exchange their cells with classmates and try to guess the function of their classmates’ cells (Cell Detective). This exercise helps students visualize how the organelles of a cell work together to perform a specific function, allows instructors to clarify misconceptions regarding cell structure, guides students away from that quintessential but unrealistic model cell found in most biology textbooks, and reinforces the central biological connection between form and function.

Read the Essay Article about how author HN Tinsley adapted this lesson for online in "Online Adaptation of the Cell Engineer/Detective Lesson"

With the publishing of the Vision and Change report, we know it is best practice to include authentic research experiences in our undergraduate science lab classes. One big challenge in teaching so-called "wet lab" classes is figuring out a way to make sure students come to lab prepared to successfully complete their experiments. Molecular biology protocols are particularly challenging as they are typically long, detailed, and have multiple steps to complete. The most successful teaching practice I have tried is having students prepare for lab by hand-drawing flowcharts of the lab protocols. Drawing is a proven way to increase scientific understanding and requires students to engage with the lab materials before class. These flowcharts are due when students walk in to lab and more importantly, students use their flowcharts during lab. This teaching tool is easy to teach to students, simple to assess, and does not rely on any pre-existing knowledge of molecular biology or artistic skill. I have had great success using flowcharts as a teaching tool in both upper division and lower division classes as well as with both life science major and non-major students. Flowcharts have many potential applications beyond undergraduate "wet lab" classes including discussion courses and graduate research projects.

A long-standing tradition uses strings of poppit beads of different colors to model meiosis, especially to show how segments of paired homologous chromosomes are recombined. Our use of orthodontic latex bands to model cohesion of sister chromatids, and plastic coffee stirrers as microtubules, extends what can normally be achieved with ‘standard’ commercial kits of beads, so emphasizing the importance of four key elements of meiosis: (a) the role of chromosome replication before meiosis itself begins; (b) pairing and exchange (chiasma formation) of homologous chromosomes during meiosis I; (c) centromere (kinetochore) attachment and orientation within/on the spindle during meiosis I and meiosis II; and (d) the differential loss of arm and centromere cohesion at onset of anaphase I and anaphase II. These are essential elements of meiosis that students best need to visualize, not just read and think about. Bead modeling leads them in that direction, as our gallery of figures and accompanying text show.

Primary image: Unassembled components of ‘PoppitMeiosis’ – a poppit bead exercise aimed at student learning of meiosis. Beads are snapped together to model bivalent chromosomes (on the right side), with double-stick tape (top) representing the synaptonemal complex, orthodontic latex bands representing cohesion rings, and coffee stirrers representing microtubule bundles that connect centromeres to the spindle poles.

Photosynthesis is a conceptually challenging topic. The small scale at which photosynthesis takes place makes it difficult for students to visualize what is occurring, and students are often overwhelmed by all of the details of the process. This activity uses a freely-available comic to make learning photosynthesis more approachable and to help students identify their own misconceptions and questions about the process. This activity is appropriate for any college-level introductory biology course and although it was designed for an online class, it could be adapted for in-person learning. In this activity, students work through a four-part online module. Each part consists of readings and videos containing background information on the steps of photosynthesis followed by the corresponding portion of a comic on photosynthesis. Students then use the background information in the module and the comic to identify their own misconceptions and questions and post these in an online discussion forum. The online module is followed by a live session in which the instructor uses the student discussion posts to clarify any remaining questions. Learning about photosynthesis in the unique visual format of a comic allows students to more easily visualize a process that they cannot see with their own eyes. Students enjoyed this activity because it makes learning photosynthesis fun and less intimidating. This lesson is powerful because it allows the instructor to hear from all students in the course via the discussion forum and then tailor the live discussion session to cover student identified problem topics.

Primary Image: Overview of photosynthesis comic. This image comes from Jay Hosler’s comic Photosynthesis or “gimme some sugar” (© 2020 Jay Hosler, used with permission from the author).