Begin the lesson by introducing the essential question: 'How do DNA and chromosomes work together to determine whether an individual will be lactose intolerant?' Engage students by sharing a real-life scenario, such as 'My friend can't have milk products. Why?' Then, organize a 'Genetic Detective' scavenger hunt where students work in small groups to solve a series of clues related to chromosomes and alleles. These clues will lead them to uncover how genetic factors contribute to lactose intolerance. Provide each group with a set of clue cards that include riddles or puzzles about genetic concepts, such as alleles and inheritance patterns. Use this activity to spark curiosity and lay the groundwork for deeper exploration. (15 minutes)

Facilitate a hands-on experiment where students simulate genetic inheritance using Punnett Squares. Begin by briefly explaining alleles and how traits are inherited, using lactose intolerance as the context. Provide students with the genotypes of two hypothetical parents, and guide them in using Punnett Squares to predict the likelihood of their offspring being lactose intolerant. Have students work in pairs to complete the Punnett Square and discuss their results. Encourage them to think critically about how alleles interact and influence traits. This activity will help students visualize inheritance patterns and apply their understanding of genetic principles in a real-world scenario. (15 minutes)

Transition into a role-play activity where students act as genetic counselors. Assign each student or pair a mock family scenario, and ask them to explain the inheritance patterns and probabilities of lactose intolerance to their 'family.' Encourage creativity and clarity in their explanations, emphasizing the role of DNA and chromosomes. Following the role-play, organize a peer review session where students present their scenarios to classmates, who provide constructive feedback on the accuracy and clarity of the information presented. This peer review process will not only reinforce their understanding but also enhance their communication skills, as they learn to articulate complex genetic concepts effectively. (15 minutes)