Learning something new can be exciting for many of us especially when we are give time to explore the “What if’s” and the “How would’s”. Understanding how traits are inherited have always been my favorite topic in biology to learn and to teach. However, completing Punnett square after Punnett square is boring and never really gives students the time to explore why the inheritance unit is a favorite. I have developed two activities to increase student engagement and thus learning of inheritance unit.
I adapted one of the first activities from multiple Process oriented guided inquiry learning (POGIL). In the Genetics Basics POGIL 2015 students learned key terms in genetics: genotype, phenotype, homozygous dominant, homozygous recessive, and heterozygous and to compare traits with a partner. (Note: this was a handout I gave for substitute because I was out getting my pin for National Board Certification). For a lesson given to substitute many of the students did well on this assignment. I think what challenge my students the most was predicting their own genotype based upon phenotype. For those who struggled with this section I provided these students with additional instructions. So perhaps the instructions weren’t completely clear.
The next lesson I thought would really peak their interests and questions. The lesson “Face Lab”. (Capture sheet for face lab: Face Lab part 1). Students working in pairs create a face based on specific traits. Students flip coins to determine sex, and the genotypes of the following traits, face shape, hair type, eye color (multiple allele), skin color (multiple allele), eye brow type, dimples, and a few others. Students determine the genotypes when each partner flips a coin, heads results in the dominant allele, and tails results in the recessive allele. Students are given example of the phenotypes so they can draw the traits on to ‘their child’. The next day I pair up two groups so that they can see the results of crossing their ‘offspring’ and for students to learn terms P generation, F1 generation and F2 generation. In addition students are given a few word problem Punnett squares to complete. Questions from the students began to generate: “Why do I have blue eyes, when both my parents have brown?” And I also saw independent thinking and speculation: “So the reason, why I am light skinned and my brother is dark skinned, is because my mom is light skinned and my dad has darker skin?”. Yes this is what I wanted to hear and see from my students! I also wanted to know if they understood that a recessive allele could be hidden for a generation and then just seem appear.
I assessed their learning by providing students with this mid-unit assessment. John’s Cockateils (john’scockateils) requires students to consider all possible offspring for two parents based upon the information given. This assessment checks students’ understanding and application of genotype, phenotype, homozygous (dominant and recessive) and heterozygous. To aid in students learning experience for this assessment I provided the students with only comments and then encouraged students to resubmit the assignment with their modifications. Here is an example of students’ work with my comments and rewrite based upon my comments.
I also had a student tweet me for extra support. The mid-unit assessment gave me the opportunity to see where students needed the most assistance. By only providing comments, students receive an opportunity for a final rewrite before receiving a grade, thus building their confidence with monohybrid crosses.
When I introduced dihybrid cross, incomplete dominance, and co-dominance, students began to confuse a simple Monohybrid cross with these non-Menedelian crosses. I wanted my students to build their understand of the ways that traits can be inherited. The genetics project gave students the opportunity to play with the vocabulary as they never had the opportunity before. Playing is the best way for learning to occur, right! I encourage students to create a male and female critter which demonstrated at least 3 monohybrid crosses, 1 co-dominant trait, 1 incomplete trait and to show 1 dihybrid cross. I modeled an example for which students could use as a tool to create their own. See my example below.
Giving time for students create and explain inheritable traits did take longer than I expected however, students gained a better understanding of all the concepts especially for those students who focused on the assignment and took extra time in class, at lunch, and after school to complete their assignment. Here are some more examples:
I see these examples as turning students to seeing inheritance as a favorite unit for all.
Jennifer L. Gable is a NBCT in AYA Biology since 2014. She teaches at Gaithersburg High School in Montgomery County MD since 2008. Life is learning, learning is fun; there for life is fun!