These cell lessons can be used by professional developers who are using CTS sections II,III, and V, to help teachers apply CTS to design of instruction. The lesson clearly shows how a careful study of the benchmarks, combined with principles of teaching and learning, can lead to development of lessons that are well-aligned with learning goals. This particular example illustrates how two CTS guides (Cells and Systems) can be used to design instruction.
AAAS (1997). Resources for Science Literacy. New York, NY: Oxford University Press. http://www.project2061.org/publications/rsl/online/GUIDE/CH2/IDESIGN.HTM