An understanding of genetics can help students participate in conversations about issues in science and technology. However, genetics content is not only complex but also abstract and difficult to connect to the everyday lives and interests of students, which can subtract from the excitement of learning about it. Haga (2006) argued that although there is a high level of support for research and testing in genetics, there is very little conceptual understanding of it. As a result, teaching genetics in the high school classroom can be challenging for both teachers and students. How, then, can science instruction help students and teachers engage in relevant genetics content that stimulates student learning and heightens curiosity?
According to the National Research Council (NRC, 2000), achieving scientific literacy will require changes in how teachers approach science teaching. The NRC (2000) emphasizes a new way of teaching and learning about science that reflects the science discipline and implies changes in what and how students are taught and in how students are assessed. Project-based science is one approach that deviates from traditional transmission methods of learning and promotes the building of knowledge. This approach has the potential to enhance students' subject-matter knowledge and thinking in science classrooms (NRC, 2000; Krajcik & Blumenfeld, 2006).
Project-based science engages students in real and meaningful problems that are potentially important to the learners and that are similar to what scientists do in the field (Krajcik & Blumenfeld, 2006). In project-based learning environments, students encounter five essential features (Krajcik et al., 2000; Krajcik & Blumenfeld, 2006): (1) a driving question, or a central question, that guides instruction and that learners find meaningful and important; (2) situated inquiry, in which students investigate specific questions and problems that are central to the unit; (3) collaborations, in which students' learning opportunities are extended beyond the individual to include other members of the learning environment; (4) technology, which serves as a cognitive tool to enhance learning (Krajcik et al., 2000); and (5) creation of artifacts, whereby students create an external representation of their understanding.
Teachers can establish a learning environment that fosters student construction of knowledge in different age groups, achievement levels, and content areas, such as genetics. Here, we describe how we use project-based science features as a framework for the design and enactment of a genetics unit and discuss some of the challenges encountered.
The unit was developed for 9th- or 10th-grade introductory biology students and aims to help students understand the connections between genes, proteins, and physical characteristics, as well as more current ideas in genomics. Many of the learning goals for the unit are consistent with national science standards (see Table 1 for an overview of the unit). Students begin learning about genetics by exploring similarities and differences at the phenotypic level. As they progress through the curriculum, they explore different biological levels.
Project-based Features of the Unit
The "driving question" organizes principles and concepts and drives many of the activities throughout the unit (Krajcik et al., 1994; Krajcik & Blumenfeld, 2006). According to Krajcik and Blumenfeld (2006, p. 655), the driving question "provides a context in which students can use and explore learning goals and scientific practices, and provides continuity and coherence to the full range of project activities." Students design and perform investigations to answer the question, which should be relevant to national and district science standards, contextualized in real-world examples and problems, meaningful and exciting to the learners, and ethical (Krajcik & Blumenfeld, 2006). …