Mendelian Genetics: Why Are the Stem and Leaf Color Traits of the Wisconsin Fast Plant Inherited in a Predictable Pattern?

Victor Sampson, Patric Enderle, Leeanne Gleim, Jonathon Grooms, Melanie Hester, Sherry Southerland, and Kristin Wilson
Type Category
Instructional Materials
Lesson/Lesson Plan
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



In this lab activity from the book Argument-Driven Inquiry in Biology, students use an online simulation ( to cross Wisconsin Fast Plants with different traits and identify inheritance patterns, enabling them to analyze data collected over several generations. The simulation offers the opportunity for students to visualize these data, traditionally collected over a long period of time, something that is often difficult for students. After identifying patterns of inheritances, students develop a model that predicts how traits are inherited in these plants. Students test their model by running the online simulations over several generations to determine the validity of their prediction. When students have finished collecting and analyzing data, they develop an argument for their investigation. They prepare a whiteboard presentation that includes the guiding question, claim, evidence, and justification of evidence and present it to the whole class in a round-robin format. After collecting feedback, students return to their original small groups for editing and revising before writing a final report. The book includes an option to extend the lesson by asking students to complete a double-blind peer review of the argument using a rubric provided in the appendix.

Intended Audience

Educator and learner
Educational Level
  • High School
Access Restrictions

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Performance Expectations

HS-LS3-3 Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in a population.

Clarification Statement: Emphasis is on the use of mathematics to describe the probability of traits as it relates to genetic and environmental factors in the expression of traits.

Assessment Boundary: Assessment does not include Hardy-Weinberg calculations.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
Teachers and students can access the simulation through the following link: Teachers should learn how to use the simulation before assigning the lab to students. This lab activity should be implemented with students working in groups of 3-4 students because of the collaboration and argumentation activities. It is important for teachers to rotate among the groups to keep students on task and model good scientific questioning and argumentation. The book states that the purpose of the lab is to introduce students to the underlying mechanisms that influence how traits are inherited. However, students need prior knowledge of Mendelian genetics and experimental design to successfully complete this lab activity. If students are unfamiliar with the argumentation strategy and scientific writing, teachers can use scaffolding to model and provide examples at each step of the lesson. Prior to using this activity, teachers can engage students by asking them to create a bracelet using data such attached earlobes and tongue-rolling of the entire class. Provide students with pictures (dominant and recessive) of three to four traits such as attached earlobes, hitchhiker’s thumb, tongue-rolling, and widow’s peak. Students identify their traits and create a bracelet using a color-coded key. The teacher can ask why all the bracelets do not look alike and use the discussion to introduce basic genetic terminology. This data can be used in the reflective discussion at the end of the lesson to help students understand the limitation of small populations and actually populations in the field.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
Students cross two Wisconsin Fast Plants with specific traits, look for a predictable pattern of inheritance, use the data collected to develop a model that explains the phenotypes of the next generation and justify their results. During the closing discussion, teachers should encourage students to reflect on the strengths, weaknesses, and revisions of their investigation. Teachers need to provide instruction and model how to provide critical and positive feedback during the argumentation stage of the lesson.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
The teacher’s notes include a brief summary of the content needed for this activity. Students need prior instruction on basic genetic terminology and laws of inheritance. They must understand the relationship between a gene and allele, law of dominance, and that the law of segregation is a result of meiosis. Students will need to know how to manipulate and analyze Punnett squares. During the discussion phase of this lesson, teachers can probe students about what role environmental factors had on their results.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
Students run online simulations to collect data on stem and leaf color trait in Wisconsin Fast Plants. They use this data make claim about the patterns of inheritance of stem and leaf color traits. The book does not provide data collection sheet for the online simulations. A teacher-created data sheet will support students in quantifying their observations and looking for patterns and trends in their data.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This lab activity involves students in all three dimensions of the Next Generation Science Standards, as they cross Wisconsin Fast Plants to collect data on traits in a population, apply their knowledge of meiosis in developing their claim, and use the empirical evidence to develop an evidence-based argument about cause and effect of stem and leaf color traits. The Teacher Notes includes a table that shows alignment to the standards for each of the 27 lab investigations. To support lesson planning, each investigation has been aligned with A Framework for K-12 Science Education; CCSS ELA, and CCSS Mathematics. The tables also outline specific concepts, which are described as supporting ideas that are addressed in each activity. The book provides some instructional strategies to support the implementation process, but the teachers need to model and provide examples of asking good questions and designing effective experiments.

  • Instructional Supports: The teacher’s notes for each investigation include information about the purpose of the lab, background and new content, the time needed to implement each state of the model for the lab, the materials needed, and hints for implementation. The book provides suggestions on how to encourage students to reflect on the strengths and weaknesses of their investigations and ways to improve the way they design future investigations. To provide additional support, four appendixes are included: standards alignment matrixes, options for implementing argument-driven inquiry lab investigations, investigation proposal options, and peer-review guide and instructor scoring rubric. A detailed step-by-step guide that explains the argument-driven inquiry is included for teachers not familiar with the model.

  • Monitoring Student Progress: Each lab investigation includes a set of checkout questions. The questions target the key ideas, crosscutting concepts, and the nature of science concepts for each of the 27 lab activities. Teachers must act as facilitators and resources for the students. They should rotate among the groups asking probing questions and listen to students’ questions and answers. Students should be encouraged to answer their own questions and should be allowed to fail in order to develop new solutions. Teachers can use the students’ responses, whiteboard presentations, and scientific report to determine if students learned what they needed during the lab or if additional teaching is required.

  • Quality of Technological Interactivity: The link is written in an old html and teachers must go into system preferences and add security exception to Java to run the simulation. Direction for unblocking the web page can be found in the following link: