Slaying The Genetics Dragon
Lesson 9 of 13
Objective: SWBAT analyze key concepts in genetics as they utilize probability to determine the variations in the genetic outcomes of this activity
Biology Brain Dump - Students will have two minutes to write down everything they know about genetics. The topics can range anywhere from pea plants, to human karyotypes or genetic disorders. Students are encouraged to dig deep and include everything and anything that they can recall about genetics. When students have exhausted their knowledge of genetics, they will draw a line underneath their last fact.
Two Brains Are Better Than One - After the two minutes are complete, students will conference with their partner to identify additional details that were listed on each other's paper. Students will have one minute to write down these ideas on to their own papers. The students will draw a line under their collaborative notes after the time limit has been announced by the teacher.
The Power of Four - Then the collaborative pair will join another pair to make a group of four students. These students will share their genetics knowledge in an effort to make a master list of understanding. This final rotation of collaboration will last one minute.
Show and Tell - Upon completion of the group work, student volunteers will share their most interesting details with the class in a whole-group discussion.
Students are encouraged to use these collaborative notes as a study guide in preparation for the unit assessment.
The video clip will provide a detailed procedure for today's activity.
Each student will need their own activity handout to record the following genetic information:
- The genotypes for the mother and father dragons
- The contributing allele from the egg and the sperm (determined by a flip of the Popsicle stick - see video clip for demonstration)
- The resulting phenotype of the dragon offspring for each trait
- Comprehension questions to conclude the activity
Each group will also need a set of color-coded Popsicle sticks. You can invest in rainbow-colored Popsicle sticks and write the the alleles on each side with marker or you can purchase plain wood-colored sticks and glue colored paper that contain the allele combination on each side of the stick. Both options are effective to promote student learning in this activity and only depends on the teacher preference and available resources.
Genes Contained On Each Popsicle Stick:
- Green Popsicle Sticks - chin spike, nose spike, head flaps, ear holes, eye points
- Red Popsicle Sticks - neck length, back hump, back spike, tail length, feet shape
- Orange Popsicle Sticks - eye color spots on the neck, wings, fangs, spots on back
- Yellow Popsicle Sticks - spots on thigh, body color, comb on head, spot color, elbow spot
- Pink/Blue Popsicle Sticks - gender , pointed thigh, number of toes, chest plate, tail spike, arm length fire breathing ability
There is also a Dragon Genetics Introduction Student Handout that will guide students through this activity.
Using the provided set of colored Popsicle sticks, students will record the genotypes for each of the provided dragon traits into the Dragon Genetics Student Data Table on the activity record sheet by identifying the letter combination found on each side of the Popsicle stick (one letter from the front and the corresponding letter from the back)
Example To Determine Genotype For A Trait: The first letter on the front is capital "A" and the first letter on the back is lower case "a". The genotype of the parent for this trait would be heterozygous Aa. The student "dragon parent
Each student (the mother and father dragons) will then flip their Popsicle sticks to determine which allele they will contribute in the creation of their offspring. Referring back to the example above: If the student flipped the Popsicle stick and the side "A" was face up then that parent would contribute the "A" allele to the offspring. Both students would record this information in their activity handout data table.
Filling In The Data Table: The students will continue this pattern until the entire data table is complete. Collaborative student pairs need to ensure that both partners have recorded each other's genetic information so their data tables are complete. Both partners will have the same data for their dragon baby. Other collaborative groups will display different data based on the outcomes of their Popsicle flipping experiences.
Once the data table is filled out, the students will use Dragon Genetics Gene Decoding Sheet to determine which phenotype corresponds to the offspring's established genotype.
Dragon Genetics Student Work #1 - These students had a great time completing the activity, but need more guidance to support their written responses for the conclusion questions.
Dragon Genetics - Student Work #2 - These students completed their data table with exemplary quality, but did not take the time to complete the conclusion questions.
Teacher Note - Since both sample groups displayed difficulties completing the conclusion questions accurately, it is crucial that the class review the genetic concepts that are associated with this lesson. Another option would be to provide students additional class time to complete all of their classwork.
Partner Data Analysis: The teacher will select one dragon trait (or two if there is time!) for the student pairs to analyze by creating a Punnett square. Students will use the parental dragons' genotypes to create the Punnett square. It is important to remind students that Punnett squares do not predict the exact outcome of a genetic cross, rather the Punnett square provides the probability of a trait being expressed.
Students will then examine their Punnett square and compare their "real" outcome to the probability given through the Punnett square. Students will construct a reflection statement that compares their actual results versus the ratio that was derived mathematically using the Punnett square.
Calculating Class Data: Each group is given the opportunity to record the genotype and resulting phenotype of their baby dragon for the teacher's selected trait. The class will compile their results on the front board so all of the students can view the data. Students will respond to the following prompts in complete sentences and incorporating the data from the activity:
- How does the genotype of your baby dragon compare to the rest of the class? Use the options of homozygous dominant, heterozygous, and homozygous recessive.
- How does the phenotype of your baby dragon compare to the rest of the class?
- Why do you think your results were the same/different than the results experienced by the other dragon parents (peers) in the class?
- What does this experience teach you using math and probability to explain the variation of traits that are observed in a population (dragons)?
Students will use the Dragon Genetics Phenotype Handout to visualize each dragon trait in order to design their dragon offspring. Since many students are not familiar with these mythical creatures, students are encouraged to use the illustrations for each trait to spark their imaginations. Some students took a "cute" approach and wanted their dragon offspring to resemble adorable bundles of joy we appreciate as humans. Other students used their appreciation of science fiction and created detailed representations of these creatures. No mater what approach students took in the creation of their dragon baby portraits, all students were able to reinforce and apply their understanding of genetic principles and have a great time!
Close - Dragon Insight
Students will reflect on today's experience and identify the following topics by employing the 3-2-1 reflection strategy:
- Three facts/lessons that were mastered through this experience
- Two facts/concepts that are still confusing after this lessonO
- One idea that they would like to learn more about