How Gene Mutations Change Your Ability to Taste

Overview

Explore genetic variation through the world of taste in this problem-solving lesson plan. Working both individually and collaboratively, students figure out what kind of tasters they are, what this means about their own genetics, and how genetic mutations can lead to functional differences. This activity provides a hands-on, personalized opportunity to learn about how genotypes and phenotypes align.

NGSS Alignment

This lesson helps students prepare for these Next Generation Science Standards Performance Expectations:

• MS-LS3-1. Develop and use a model to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism.
• MS-LS3-2. Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation.

This lesson focuses on these aspects of NGSS Three Dimensional Learning:

Science & Engineering Practices	Disciplinary Core Ideas	Crosscutting Concepts
Asking Questions and Defining Problems. Ask questions that arise from careful observation of phenomena, models, or unexpected results, to clarify and/or seek additional information. Analyzing and Interpreting Data. Analyze and interpret data to provide evidence for phenomena. Constructing Explanations and Designing Solutions. Apply scientific reasoning to show why the data or evidence is adequate for the explanation or conclusion. Engaging in Argument from Evidence. Construct, use, and/or present an oral and written argument supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon or a solution to a problem.	LS3.A: Inheritance of Traits Genes are located in the chromosomes of cells, with each chromosome pair containing two variants of each of many distinct genes. Each distinct gene chiefly controls the production of specific proteins, which in turn affects the traits of the individual. Changes (mutations) to genes can result in changes to proteins, which can affect the structures and functions of the organism and thereby change traits. Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited. LS3.B: Variation of Traits In addition to variations that arise from sexual reproduction, genetic information can be altered because of mutations. Though rare, mutations may result in changes to the structure and function of proteins. Some changes are beneficial, others harmful, and some neutral to the organism.	Structure and Function. Complex and microscopic structures and systems can be visualized, modeled, and used to describe how their function depends on the shapes, composition, and relationships among its parts, therefore complex natural structures/systems can be analyzed to determine how they function. Cause and Effect: Mechanism and Prediction. Cause and effect relationships may be used to predict phenomena in natural or designed systems.

Materials

Materials for each student:

• Paper test strip, control (1); available from Carolina Biologial.
• Paper test strip, PTC (1); available from Carolina Biological.
• Handouts with "taster" or "non-taster" gene sequence (2 sequences per student). Each student gets two sequences dependent on his/her observed phenotype ("taster," "non-taster," or "in-between").
• Stickers or colored armbands, etc., that you can use to color-code students according to their phenotype.