Punnet Square
First ask questions: How does genetic information impact an offspring’s trait? What are the possible outcomes of the dominant and recessive traits? Why do we use capital letters for an allele and lowercase letters for the other? What do the boxes in the Punnett squares represent? What is the physical appearance or observable trait called? What is the ratio of various observable traits? Can you correctly complete the array for gene combination, or genotypes, for their offspring? What phenotype, or evidence of a dominant or recessive trait, will each combination have?
These questions are written on a chart and used as an active questioning chart, with questions answered and more added as the class progresses through the activity. Students will receive background vocabulary related to the Punnett square activity so they can familiarize themselves with what the activity represents. The teacher will model several.
Then, the teacher displays a complete diagram of Parent 1 and Parent 2 as an example of how students will complete their Punnett square activity. The squares represent possible combinations of genes that offspring can inherit from two parents. Students will complete a basic Punnett square using their parents' genotypes: free and unattached earlobes, black and brown eyes, frizzy and straight hair. As students learn about traits, they will complete the activity. As a class, conduct a challenging activity with the teacher. Complete a Punnett square activity on rabbits with a solid coat and stand-up ears, and a spotted coat and floppy ears. After completing the chart, students answer questions about the diagram. Based on their questions, students can move on to the strawberry activity about food. Before, during, and after the activities, the teacher and students are questioning during the lessons.
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