Exposure Science: Lesson Plan

Learn how the environment can affect gene expression, and discover how researchers in North Carolina are investigating drug safety and unusual, genetically mediated responses to drugs.

UNC-TV Media

Alignment to NC Essential Standards

  • NCES.Bio.3.2.3 — Explain how the environment can influence the expression of genetic traits.

Learning Outcomes

Time Allotment Needed: 5 days (block schedule)

  • Students will cite examples of environmental factors that affect gene expression.
  • Students will discuss the importance of drug safety and how drugs are tested and evaluated for safety.

Essential Questions

  1. How do environmental factors affect the expression of a genetic trait?
  2. How can an individual's cell structure or genetic traits contribute to a rare drug reaction?

Essential Vocabulary

  • DNA
  • Epigenetics
  • Genetic trait
  • Over-the-counter drug
  • Pharmaceutical
  • Prescription drug
  • Toxicity


Students will view the NC Science Now video The 99% Solution. After viewing the video, students should answer the following questions. They can then discuss their answers with a partner or in small groups.

  1. What percentage of patients take an over-the-counter medication and experience no problems with it?
  2. What are the economic consequences of bad drug reactions?
  3. As described in the video, what is the special mission of The Hamner-UNC Institute for Drug Safety Sciences? Why is this mission important? 
  4. What are some potential reasons why a patient may have a unique or unusual reaction to a medication?
  5. Why are scientists studying the genes of patients who have rare drug reactions?
  6. How can the work of the UNC scientists help make medications both more effective and less expensive?


Students will work independently to gather information about genes, gene expression, and the factors that affect gene expression. Students should take notes to document their research, citing the website at which they obtained the information.



Students will work in small groups to research examples of traits that are controlled or influenced by genes, and the different ways that the traits can be expressed due to environmental factors or other factors. The class may research traits in humans or other organisms, including farm crops, live stock, or wild plants and animals. Useful examples to research include genetically inherited diseases, such as Huntington's Disease and Cystic Fibrosis, as well as diseases with a genetic component, such as many types of cancer. Abilities in math, music and other disciplines have also been proposed to have both genetic and environmental factors. Have students discuss their findings with group members.


Students will view the NC Science Now video Exposure Science. After viewing the video, a class discussion should include the following topics/questions:

  1. What are three chemical sources that people interact with on a daily basis, according to the video?
  2. What is a “concentration response” test, and what does it measure?
  3. Why do you think the chemicals in food are studied more carefully than the chemicals we come into contact with every day, such as those in water bottles and clothing? Do you agree with this priority? Why or why not?


Students will prepare a written report or a computer presentation to communicate the information they learned about genes, gene expression and the effect of the environment on genetic traits. The report may focus on any combination of topics from this lesson, and may be supplemented by additional topics of special interest. Encourage students to conduct additional research to expand and develop their report, as well as to include personal examples or anecdotes if applicable. Remind students to cite the sources of the information they present. These sources may include NC Science NOW videos, trustworthy Internet sites, interview subjects, printed reference books and journal articles.