Taster/Non-taster Lab Activity

Purpose: This activity is designed to involve students, family members, and other peers in the process of determining whether someone can be classified as a “taster” or “non-taster”.

Overview: The study of genetics/inherited traits is more than just tracing back or predicting eye and hair color. Our genetic code is specific from one person to another. We do pass on other, more “unusual” traits, such as the ability to discern specific tastes in foods. [9-12 Content Standard C- Molecular basis of heredity]

Objectives: Students will be able to:

1. Determine whether he/she is a taster or non-taster.

2. Test selected individuals from his/her family and peer group for the trait.

3. Chart all findings from all students to determine which trait is dominant.

Materials:

· Large piece of paper

· PTC taste paper

· Sodium Benzoate taste paper

· Thiourea taste paper

· Control taste paper

· Envelopes containing three complete sets of taste papers, numbered to match the sequence of the activity.

· Paper cups for water [Teaching Standard D- Make accessible science tools]

Procedures:

1. Students will share traits they know are dominant in their immediate families and peer groups. Ex. Hair color, eye color… list traits and post.

2. Students number 1-5 on notebook paper

3. Distribute cups of water to cleanse palate

4. Distribute PTC taste paper, one to each student with instructions to taste the paper, and without sharing with others, write down what it tasted like. It’s O.K. if it tastes like nothing, or like paper. (that would be the control!!) It could also taste salty, sweet, bitter, hot,…

5. Continue with the other taste papers, students recording how each paper tasted. [Content Standard Unifying Concepts- Change, constancy, and measurement]

6. Collect results and graph the data on a large piece of paper. (save)

7. Using the chart, predict which trait (taster or non-taster) is dominant in their families and in the general population

8. Assignment: Each student will take three complete sets of taste paper home to test parents and one friend. Test papers are to be numbered to correspond with the sequence of the previous activity.

Tying it all together: [Teaching Standard B- Orchestrate scientific discourse]

Students will share their experiences with their families and friends. Students can place tally marks on the previous days chart. Discuss whether their predictions were correct. Analyze findings.

Follow up activities could include the construction of a punnett square using the information collected from parents. [9-12 Content Standard A- Use mathematics to improve scientific communication] The percentage of offspring that are tasters could be predicted, and more testing done to check.

Some may hypothesize that people who tend to be overweight are taster, or that thinner people are non-tasters. Is this how obesity seems to run in families???? An experiment could be designed and carried out to test the hypothesis.

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