Crosscutting concepts (CCCs) are superordinate in the scientific concept system, common across disciplines, and very abstract. These characteristics, with the addition of incoherence in their curricular presentation, can challenge instructors. We designed a modular course based on coherence and conceptual understanding. The course structure was arranged in accordance with intra- and inter-unit coherence of CCCs, and each lesson was prepared according to “concept-based instruction” and the “5E instructional model.” The results of the pretest and posttest and the semi-structured interviews consistently showed that the participating high school students significantly improved their understanding of CCCs, thus supporting the effectiveness of the modular course.

The recent discovery of preserved cells and soft tissues in certain dinosaur bones seems incompatible with an age of millions of years, given the expectation that cells and soft tissues should have decayed away after millions of years. However, evidence from radiometric dating shows that dinosaur fossils are indeed millions of years old. Under certain circumstances, cells and soft tissues in bone are protected from complete disintegration. Formation of a mineral concretion around a bone protects biomolecules inside it from hydrolysis by groundwater. Infusion and coating with iron and iron compounds at a critical point in the decay process protects cells within a bone from autolysis. Cross-linking and association with bone mineral surfaces furnish added protection to collagen fibers in a bone. These protective factors can result in soft-tissue preservation that lasts millions of years. It would benefit educators to be aware of these phenomena, in order to better advise students whose acceptance of biological evolution has been challenged by young-Earth creationist arguments that are based on soft tissues in dinosaur fossils.

Core chemistry ideas can be useful tools for explaining biological phenomena, but students often have difficulty understanding these core ideas within general chemistry. Connecting these ideas to biologically relevant situations is even more difficult. These difficulties arise, in part, from a lack of explicit opportunities in relevant courses for students to practice connecting ideas across disciplines. We are developing activities that examine students' abilities to connect core chemistry ideas with biological phenomena, the overall goal being to develop a set of assessments that ask students to connect their knowledge across introductory chemistry and biology courses. Here, we describe the development and testing of an activity that focuses on concepts about energy in bond breaking, bond forming, and ATP coupling. The activity was completed by 195 students in an introductory cell and molecular biology course at Michigan State University; students were either co-enrolled or previously enrolled in General Chemistry I. Follow-up interviews to assess the validity of the activity (among others) showed that students interpreted the questions as intended and that they valued the activity as an opportunity to connect ideas across courses.

Globally, most human caloric intake is from crops that belong to the grass family (Poaceae), including sugarcane (Saccharum spp.), rice (Oryza sativa), maize (or corn, Zea mays), and wheat (Triticum aestivum). The grasses have a unique morphology and inflorescence architecture, and some have also evolved an uncommon photosynthesis pathway that confers drought and heat tolerance, the C₄ pathway. Most secondary-level students are unaware of the global value of these crops and are unfamiliar with plant science fundamentals such as grass architecture and the genetic concepts of genotype and phenotype. Green foxtail millet (Setaria viridis) is a model organism for C₄ plants and a close relative of globally important grasses, including sugarcane. It is ideal for teaching about grass morphology, the economic value of grasses, and the C₄ photosynthetic pathway. This article details a teaching module that uses S. viridis to engage entire classrooms of students in authentic research through a laboratory investigation of grass morphology, growth cycle, and genetics. This module includes protocols and assignments to guide students through the process of growing one generation of S. viridis mutants and reference wild-type plants from seed to seed, taking measurements, making critical observations of mutant phenotypes, and discussing their physiological implications.

Plastic pollution is ubiquitous and there is growing concern about its consequences. Given that current research findings often reach the public insufficiently, the issue should be addressed at school. To create a fruitful learning experience, we propose three associated hands-on, inquiry-based learning activities that require little equipment. Students learn about the origins and properties of plastics, investigate everyday sources, learn about recycling, address and reflect upon the material's (dis)advantages, and are encouraged to consider solutions. All activities align with the Next Generation Science Standards and are primarily designed for the middle school classroom; we further provide modifications for elementary and high school settings.

This hands-on lab allows students to explore concepts and quantify effects of ocean acidification. Many laboratory activities simplify ocean acidification through computer simulations or dripping acid on nonliving materials (e.g., sea shells) but do not provide adequate opportunities for students to measure, inquire, or see real consequences for living organisms. Thus, we developed this low-cost, easily accessible experiment to imitate ocean acidification on living, calcifying organisms.

Soil provides innumerable valuable ecosystem services, such as the production of food and the direct support of wildlife, by ensuring the availability of adequate habitat. However, unsustainable human activities are resulting in degradation of soils worldwide. Hence, it is of utmost importance to raise awareness about this often-overlooked environmental issue. This article presents an inquiry-based activity that challenges students to assess the ecological quality of soil in the surroundings of their classroom. Plus, students and teachers are invited to become citizen scientists by sharing their data with researchers, thus contributing to a future endeavor to map soil quality through broad geographic ranges.

Cell membrane transport is an important topic discussed in the biology classroom from the middle school to the graduate level. Membrane transport is complex, and students are often confused between different types of transport mechanisms. Dramatization is an active-learning strategy to engage students in learning. The flipped teaching method is designed to introduce lecture content prior to class meeting, thus creating time during class to adapt active-learning strategies such as dramatization. In this work, students were given a pretest prior to the dramatization activity. As each type of membrane transport was discussed, which included simple diffusion, osmosis, facilitated diffusion, and active transport, students were assigned specific roles to demonstrate the movement. The dramatization activity triggered many questions related to the topic, and these questions were addressed immediately. A posttest was conducted at the end of the dramatization activity. Our results demonstrated increases in the students' understanding, engagement, and confidence level. The combination of flipped teaching and dramatization thus serves as a student-centered active-learning strategy for teaching difficult biological concepts.

To survive, complex organisms must maintain homeostasis by coordinating the activity of interacting, hierarchical systems. This is a core biological idea in the Next Generation Science Standards and one that many students find challenging. The most common lab exercise used to introduce homeostasis – a mini-experiment in which students measure how physical activity affects their pulse and respiratory rate – fails to show any direct evidence of internal stability. In this article, we describe how modifying this lab using an inexpensive pulse oximeter rectifies this shortcoming, giving students the ability to collect laboratory data that show both change and dynamic stability.