Lesson Plan non mendelian inheritance

Lesson Plan non mendelian inheritance LEYNAR LEYTON NARANJO PH.D. STUDENT. INSTITUTE OF PLANT BREEDING, GENETICS AND GENOMICS

Author(s): Author Affiliation and Location. Author Website Author Contact Information Introduction/Abstract to Lesson Plan List of Standards Addressed Learning Objectives using Measurable Verbs (what students will be able to do) Leynar Leyton Naranjo Institute of Plant Breeding, Genetics and Genomics University of Georgia Griffin Campus Griffin, GA (Spalding County) about.me/leynar leynar@uga.edu In this lesson plan student will understand the inheritance of nonmendelian traits. They will have real data of segregation of a 3 allele trait and how it is related with leaf color and vein color in the ornamental plant elephant ear (Caladium xhortulanum). The class introduces the trait as mendelian, with only 2 alleles. In the last part of the class students will face the same trait, but with 3 alleles. GSE Biology SB3; GPS SB2c, SB2e Next Generation Science Standards: HS-LS3 Heredity, HS, LS3A: Inheritance of traits LSB3: Variation of traits Students will be able to: identify valuable traits; Discuss the inheritance of traits; Apply and interpret Punnett squares of traits with two or three alleles; Design crosses and select parents for the study of trait inheritance. Appropriate Grade Levels Grade 12, Grade 11, Grade 10 Group Size/# of students activities are designed for Setting (e.g. indoors, outdoors, lab, etc.) Approximate Time of Lesson Resources Needed for Students Resources Needed for Educators Apps/Websites Needed Optional Next Generation Science Standards All class sizes, for the activity student can work in groups of 2-4 students, but it is up to the teacher. Indoor Adaptable, Multi-day NA White board, PowerPoint, color printer, projector. NA HS-LS3 Heredity, HS, LS3A: inheritance of traits LSB3: Variation of traits 2 P a g e

Lesson Activities (step by step description) The class starts with general information about Caladium ( Elephant ear plant ) [See PowerPoint Slides] [Activity 1] [Engage] The first activity refers to the problem that some researches from Florida need our help, they found 4 accessions (plants) with different characteristics that they want to use in their breeding program. The plants that they found are described in the PowerPoint presentation. The descriptions of the plants are: - Caladium candidum : White leaves, green veins - Caladium Candidum Jr. : White leaves, green veins - Caladium Florida Fantasy : pale green leaves, red veins - Caladium Florida Red Ruffles : Red leaves with green margin, red veins The first task for the students is identify the ornamental characteristics present in this germplasm (the four plants). The traits present are vein color, leaf color, and leaf shape. [Activity 2] The main point of this activity is to focus on the trait that we will be working on: Vein color. Students need to focus on the variants of the trait present in the germplasm available, in this case, only two variants: red or green [Activity 3] [Explore] The next activity is to understand the inheritance of the trait vein color. We will start with a mendelian example, and then move forward with a non-mendelian example. Students need to answer the question: How can we test the inheritance of the trait? with the hint that the literature suggest one variant of the trait is dominant over the other. With the germplasm available students need to design a test cross for the trait and see its inheritance. There is not a wrong answer for this part, but there are crosses that make more sense than others while testing the inheritance of vein color. 3 P a g e

The progeny of each cross will be available in an envelope/box clearly identify (type of cross and parents). Student can count how many different phenotypes they have in the progeny, and calculate phenotypic ratios for the trait. Please note that as we are working with real data, some of the crosses do not follow the mendelian ratios perfectly but they are close enough to deduce them. All the possible crosses, their phenotypic ratios, and Punnett squares are detailed below. The possible crosses are organized in a relevant order (based on Mendelian laws). 4 P a g e

1.- Self-cross: This is crossing the plant with itself, taking pollen from one flower and put it on the stigma of the same flower or on the stigma of other flower in the same plant. This cross is made to check if that plant is homozygous or heterozygous for the trait. If the plant is homozygous (dominant or recessive), the progeny should be 100% as the mother plant. If the plant is heterozygous, the progeny should segregate. In the case of selfing plants with green veins the progeny would be 100% green vein, and in the case of selfing plants with red veins the progeny would be 75% red, 25% green (ratio 3:1) HOMOZYGOUS DOMINANT HOMOZYGOUS RECESSIVE HETEROZYGOUS 2.- Cross Green vein x Green vein: This is crossing a green vein plant with other (different cultivar, for example Candidum x Candidum Jr. ) green vein plant; taking pollen from the flower of a green vein plant and put it on the stigma of a flower of other green vein plant. If we do such a cross we get a progeny that is 100% green vein, which suggest that both plants are homozygous (dominant or recessive), or one is homozygous dominant (AA) and the other is heterozygous (Aa). 5 P a g e

3.- Cross Red vein x Red vein: If we cross a red vein plant with other (different cultivar) red vein plant taking pollen from a red vein plant and put it on a stigma of a flower of other red vein plant, or vice versa the progeny is 75% red and 25% green (ratio 3:1). This result suggests that both plants are heterozygous (Aa) is the only combination that will result in a progeny with ratio 3:1. 4.- Cross Green vein x Red vein: If we cross a red vein plant with a green vein plant taking pollen from a plant with red veins and put it on a stigma of a flower of a green vein plant, or vice versa We get a progeny 50% red vein and 50% green vein. This result suggest that one plant is heterozygous and the other is homozygous recessive. 6 P a g e

[Activity 4] [explain] In this part, students are asked to report the phenotypic ratios of their first cross, which are the possible genotypes, and to make the Punnett squares of the cross if possible. [Activity 5] [Explain] Now that the students made a hypothesis about the genotype of their first cross, they can do a test cross to prove their hypothesis, or to gather more information. (all the possible crosses are detailed above). With the information of their second cross they should be able reject/support their hypothesis and to propose an inheritance model for the trait. The inheritance of the trait is one gene with two alleles. Where will call A to de dominant allele and a to the recessive allele. The dominant allele A (red vein color) is dominant over the recessive allele a (green vein color). [Activity 6] [Elaborate] [non-mendelian part of the class] In this part students are told that the researchers found two new plants with white veins. They need to know how this new variant of the trait interact with the red (A) and green (a) alleles we just discus about. Again, students are asked to do a test cross and to stablish phenotypic ratios, Punnett squares and possible inheritance model for the white vein trait. The literature suggest that the white color is dominant. Types of crosses that students can do: 1.- Selfing white vein plants: If they self white veins plants, the progeny will be 75% white and 25% green (3:1 ratio). We saw previously that the only combination that will produce this type of segregation ratio is both plants being heterozygous 7 P a g e

2.- Crossing a white vein plant with a red vein plant: If we cross a heterozygous white vein plant ( A White, a Green) with a heterozygous red vein plant ( A Red, a green) or vice versa the progeny will be 25% White, 50% Red, and 25% Green (ratio 1:2:1). The only explanation for that phenotypic ratio is a non-mendelian inheritance of the trait. Where red is dominant over white and green, white dominant over green, and green is recessive. 3.- Crossing a white vein plant with a green vein plant: If we cross a white vein plant (Aa) with a green vein plant (aa). The progeny will be 50% White, 50% Green (1:1 Ratio). The students should realize based in the crosses made and the guidance of the teacher, that the trait is controlled by one gene with 3 alleles that we will call A WHITE, A RED, a GREEN where A RED > A WHITE > a GREEN Meaning that the red allele is dominant over all the other alleles, the white allele is only dominant over the green allele and the green allele is recessive. 8 P a g e

Assessment/Evaluation Activity number 6 can be done as a homework assignment. In any of the activities proposed the teacher can evaluate the learning of the student based on the answers to the different crosses and the hypothesis (Punnett squares, Phenotypic ratios, and Genotypes) proposed by the students. Images Available in Slides (See attachments) Appendices Description of the crosses. (Progeny) Background Reading for Teachers Reference paper in which this lesson plan was based Zhanao, Deng and Harbaugh, Brent K. 2006. Independent inheritance of leaf shape and main vein color in caladium. Journal of the American Society of Horticulture Science. 131(1): 53 58. Available on line: http://journal.ashspublications.org/content/131/1/53.short Feedback Form for Teachers Please feel free to contact me (leynar@uga.edu ) with any suggestion of question that you may have. I really appreciate all the comments about this lesson plan. Thanks! 9 P a g e

Appendix 1 Selfing green vein plants Cross Candidum x Candidum 10 P a g e

Progeny n = 11 1 1 Images: www.parkswholesaleplants.com. 11 P a g e

Appendix 2 Selfing green vein plants Cross Candidum Jr x Candidum Jr 12 P a g e

Progeny n = 14 2 2 Images: http://www.tallahasseegardenclub.com. 13 P a g e

Appendix 3 Crossing green vein plants Cross Candidum x Candidum Jr / Candidum Jr x Candidum 14 P a g e

Progeny n = 31 3 3 Images: Iowa State University [ISU] Extension 15 P a g e

Appendix 4 Selfing red vein plants Cross Florida Red Ruffles x Florida Red Ruffles 16 P a g e

Progeny n = 34 4 4 Green vein Caladium images: http://www.parkswholesaleplants.com, Red vein Caladium images: http://www.pikenursery.com. 17 P a g e

Appendix 5 Selfing red vein plants Cross Florida Fantasy x Florida Fantasy 18 P a g e

Progeny n = 17 5 5 Red vein caladium image: Classic Caladium http://www.classiccaladiumsllc.com/ ; Green vein caladium image: http://seedratings.com 19 P a g e

Appendix 6 Crossing red vein plants Cross Florida Fantasy x Florida Red Ruffles / Florida Red Ruffles x Florida Fantasy 20 P a g e

Progeny n = 121 6 6 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com 21 P a g e

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Appendix 7 Selfing white vein plants Cross Florida Moonlight x Florida Moonlight 24 P a g e

Progeny n = 23 7 7 White vein Caladium: http://garden.org Green vein Caladium: http://http://123rf.com 25 P a g e

Appendix 8 Selfing white vein plants Cross Aaron x Aaron 26 P a g e

Progeny n = 11 8 8 White vein Caladium: http://marlborobulb.com ; Green vein Caladium: http://123rf.com 27 P a g e

Appendix 9 Crossing white vein plants Cross Florida Moonlight x Aaron / Aaron x Florida Moonlight 28 P a g e

Progeny n = 12 9 9 White veins Caladium (9): http://www.riverbendnursery.com ; White veins Caladium (3): https://fmanos.wordpress.com 29 P a g e

Appendix 10 Crossing green vein plants x red vein plants Cross Candidum x Florida Fantasy / Florida Fantasy x Candidum 30 P a g e

Progeny n = 32 10 10 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com 31 P a g e

Appendix 11 Crossing green vein plants x red vein plants Cross Candidum x Florida Red Ruffles / Florida Red Ruffles x Candidum 32 P a g e

Progeny n = 34 11 11 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com 33 P a g e

Appendix 12 Crossing green vein plants x red vein plants Cross Candidum Jr x Florida Fantasy / Florida Fantasy x Candidum Jr 34 P a g e

Progeny n = 35 12 12 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com 35 P a g e

Appendix 13 Crossing green vein plants x red vein plants Cross Candidum Jr x Florida Red Ruffles / Florida Red Ruffles x Candidum Jr 36 P a g e

Progeny n = 32 13 13 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com 37 P a g e

Appendix 14 Crossing red vein plants x white vein plants Cross Florida Fantasy x Florida Moonlight / Florida Moonlight x Florida Fantasy 38 P a g e

Progeny n = 33 14 14 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com; White vein Caladium: http://marlborobulb.com. 39 P a g e

Appendix 15 Crossing red vein plants x white vein plants Cross Florida Fantasy x Aaron / Aaron x Florida Fantasy 40 P a g e

Progeny n = 35 15 15 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com; White vein Caladium: http://marlborobulb.com. 41 P a g e

Appendix 16 Crossing red vein plants x white vein plants Cross Florida Red Ruffles x Florida Moonlight / Florida Moonlight x Florida Red Ruffles 42 P a g e

Progeny n = 33 16 16 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com; White vein Caladium: http://marlborobulb.com. 43 P a g e

Appendix 17 Crossing red vein plants x white vein plants Cross Florida Red Ruffles x Aaron / Aaron x Florida Red Ruffles 44 P a g e

Progeny n = 35 17 17 Red vein Caladium image: http://classiccaladiumsllc.com ; Green vein Caladium image: http://onlinneplantguide.com; White vein Caladium: http://marlborobulb.com. 45 P a g e

Appendix 18 Crossing green vein plants x white vein plants Cross Candidum x Aaron / Aaron x Candidum 46 P a g e

Progeny n = 32 18 18 White vein Caladium: http://marlborobulb.com ; Green vein Caladium: http://123rf.com. 47 P a g e

Appendix 19 Crossing green vein plants x white vein plants Cross Candidum Jr x Aaron / Aaron x Candidum Jr 48 P a g e

Progeny n = 34 19 19 White vein Caladium: http://marlborobulb.com ; Green vein Caladium: http://123rf.com. 49 P a g e

Appendix 20 Crossing green vein plants x white vein plants Cross Candidum Jr x Florida Moonlight / Florida Moonlight x Candidum Jr 50 P a g e

Progeny n = 31 20 20 White vein Caladium: http://marlborobulb.com ; Green vein Caladium: http://123rf.com. 51 P a g e

Appendix 21 Crossing green vein plants x white vein plants Cross Candidum x Florida Moonlight / Florida Moonlight x Candidum 52 P a g e

Progeny n = 34 21 21 White vein Caladium: http://marlborobulb.com ; Green vein Caladium: http://123rf.com. 53 P a g e

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