4.1 DNA: THE MOLECULE OF LIFE TE 4.1 C UNIT 4 Part A Put students into groups of four. Have students work in pairs for Part A and in a foursome for Part B. Distribute a bag with nucleotide pieces to each pair of students. Facilitate the activity by directing students to open the bag. Ask students the following questions: – How many different shapes do you observe? 4 – How many subunits does each shape contain? 3 – What does each shape have in common? a subunit labeled “ P ” and a subunit labeled “ D ” Introduce the term nucleotide to students. Direct students to draw a nucleotide in their journals. Next, instruct students to manipulate the pieces so that they fit together like pieces of a puzzle. Ask students the following questions: – What subunits differ between each shape? A, C, G, T – Do any of the pieces fit together? yes – What are the letters of the shapes that fit together? A-T and C-G Direct students to draw their completed model of DNA in their journals. Instruct students to draw a diagram of their completed structure in their journals. Check for understanding. Use Trans 31 in your class discussion. Part B Distribute bags filled with beads to each lab group. Direct students to follow the procedure on BLM 123. Circulate among groups, monitor for understanding, and redirect as needed. Conduct a class discussion. EXPLAIN– Part 1, page 254 Materials: – BLMs 124–125, DNA WebQuest – Computers with Internet access