Directions 1. Describe the unit posttest. Explain the purpose of the unit posttest to students: It will help you as a teacher understand how students think about what happens when plants move, grow, an function. It will help them think about what they learned and how their ideas changed over time. 2. Have students take the unit posttest. Administer the test online or distribute copies of 6.4 Plants Unit Posttest to be completed with paper and pencil.