Build a Bug
This first genetics classroom activity involves hands-on artwork. Provide materials for students to use to build a bug, with two types of materials for each body part. In other words, you might supply pipe cleaners and yarn for legs, pompoms and cotton balls for bodies, etc. Have each student create one bug using these materials. Then have students pair off and explain that the bugs belonging to each pair will now have offspring. Have students use a Punnett square to figure out what that offspring is likely to look like. Then have them use the materials to build four possible offspring. Have pairs discuss whether there is any offspring that their pair of bugs could not have had, and why.
The Monkey Gene Game
Divide the class into small groups, and give each group a bag full of green, black, and white jelly beans. Have students close their eyes and take turns picking out pairs of genes from the bag until they have ten different pairs of genes. Explain that each of these pairs of genes belongs to a monkey who lives in a faraway rainforest. Tell students that in these monkeys, the green gene is dominant to the black and white genes, and the black and white genes are co-dominant. Discuss with them what that means, and explain that when a monkey has a black and a white gene, it appears grey.
Explain that predators in the jungle can easily see the white monkeys because they show up against the trees, but that the green, black, and grey monkeys are camouflaged. Have students place any “white monkeys,” or monkeys with two white jellybeans, back into the bag. Then have them create a new generation of monkeys by scrambling the remaining jelly beans and choosing pairs of genes for the next generation. Explain that suddenly hunters began to capture all of the black monkeys to use their hides, and have groups remove all fully black and fully white monkeys from this second generation. Then have them create a third generation, using the same process.
Discuss the results with students. Did any genes disappear entirely? Did the black or white monkeys stop appearing in the third generation? Why do they think this was the case? Have students predict what would happen if this process continued for several generations. Then ask them to predict what would happen if the government allowed monkey hunting before the next generation was born. If time allows, have groups continue to create generations until they can see whether their predictions were correct.
Have students choose a specific genetic trait, such as hair or eye color, and have them make a genetic family tree showing how that trait has expressed itself within their extended families. Encourage them to speak with relatives about grandparents or great-grandparents, as well as to include as many aunts, uncles, and cousins as possible.
Note: Be sensitive toward any adopted or foster students in your class. You may want to avoid doing this genetics classroom activity with your class if you feel that they will be sensitive toward it. Alternatively, you can see whether they have any pictures of their extended birth family or if they would feel comfortable discussing how, although they are with family right now, they do not share the same genes. Also make sure to emphasize that students may not have information about all family members, and that it’s okay if this is the case.