Learners act as nucleotides as they build a human model of DNA. Learners' hands represent the 3' and 5' locations of the hydroxyl and triphosphate groups of each nucleotide. Learners build one strand of DNA by linking hands, then build the complementary strand. From this activity, learners can see the two strands run antiparallel. Activity contains questions as a suggested assessment. Learners should be familiar with DNA structure prior to completing this activity.