Students will sort samples of barley based on color and hull type to create histograms. They will hypothesize and investigate the outcomes of planting barley seeds of one color and planting a random mix of different colors. Students will analyze the results of barley seeds that have been planted and harvested, constructing conclusions about trait selection. Lesson developed by Barleyworld, Oregon State University in collaboration with Johannah Withrow Robinson, Briggs Middle School barleyworld.org/main/education
Barley is an ancient grain that grows well around the world. Like its relative wheat, barley is a self-pollinated grass. Self-pollination is quite common in plants. Self-pollination allows a plant to produce seeds with the same genetics as their offspring. When the seed is planted, the plant will have the same traits as the parent plant. This is very different from most animals, where the offspring are not genetically identical to a parent. Thousands of different types of barley have been grown and selected by humans for different traits for thousands of years. The process of selection is the basis of domestication and breeding of plants and animals. Some barley are covered (has a hull), and others are naked (no hull). Seed color can range from black to white. The samples used in this experiment include covered and naked barley, and barley seeds classified as black, brown or white.
Part I: Selection
1. Provide each student with a copy of the Oregon Wolfe Barley Histogram online worksheet and Selection of Oregon Wolfe Barley worksheet.
2. Provide an introduction to the activity using the Wolf Barley Selection PowerPoint.
3. Have students begin by sorting the barley on the Oregon Wolfe Barley Histogram online worksheet based on covered (has hull) vs. naked (no hull) barley.
4. After students have categorized the barley based on covered vs. naked, have students record the amount in each category on the chart on their worksheet.
5. Then, have students calculate the percentage of hulled vs. naked seed and record the answers in their chart.
6. Next, have students move the images to histogram two on the online worksheet sorting them by color. This is the process of selecting a trait used to artificially select or breed, plants and animals.
7. After students have sorted the seeds to create histogram two, they will enter the amount of seeds in each color on the data table on their worksheet.
8. Instruct students to calculate the percentage of each color in the sample and record it on the chart.
9. Next, students will reflect on the data set with a partner using the questions on their worksheet to guide their thinking.
10. Finally, facilitate a whole class discussion about the questions.
11. Have students write a hypotheses using the essential questions as a guide after thinking about the results of the data.
12. Provide time for students to share their hypothesis.
Part 2: Analyzing Results
1. Provide each student with a copy of the Analyzing Results worksheet.
2. Explain to students that they will be looking at the results of planting sets of unselected and selected barley. On their worksheet they will see seeds that were planted and the seeds that were produced from the planting.
3. Instruct students to use the data to calculate percentages for each scenario (consider reminding students of the process or guiding them through the first few calculations).
4. Then, invite students to respond to the reflection questions at the end of their worksheet.
5. Discuss reflection questions as a class.