Cracking the Genetic Code

What You Need

Cracking the Genetic Code Image Credit: National Human Genome Research Institute


To help students understand what the knowledge of DNA can tell us about ourselves and other organisms and species. Students will also learn about the systematic study of the human genome.


Young students observe general similarities and differences among organisms. As they get older, their understanding of these similarities and differences becomes more sophisticated. Ultimately, high-school students take the study of diversity and similarity to the molecular level. When high-school students get to this point in learning, they will first learn about the inner workings of cells, and how DNA, RNA, and proteins operate within the cell. The next phase is for students to understand that it is possible to infer relatedness among organisms from DNA or protein sequences.

It is always beneficial for students to learn about science through the understanding of current events and projects. An interesting and groundbreaking project that has been on the forefront of science and in the news for the past few years is the Human Genome Project (HGP), an international research program that is "mapping" the human genome and determining the complete sequence of human DNA.

Not only should students be aware of this project in general, but in understanding it they will also grasp the fact that sequencing our own DNA determines the kinship between us and other organisms and species, whether they be worms, or early hominids. The Human Genome Project also demonstrates a "careful, systematic study" in progress and how new knowledge gleaned from a study can impact our future.


Begin the lesson by having students read Genome 'Treasure Trove' on the BBCi Science website.

Once they are finished, ask the following questions:

  • What is the Human Genome? (It is all of the genes of our species—or the totality of human DNA.)
  • What were scientists working on the project surprised about? (Mainly, how alike humans are to one another genetically.)
  • How do humans compare (genetically) to flies, worms, mice, and other animals? (Humans have only a relatively modest number more genes than these other animals.)
  • Do you think that we could predict how similar or different organisms would be if we only had the DNA sequences to look at (and not external features)? (Answers will vary.)
  • How have scientists gotten to this point of discovery? (Students may not be equipped to answer this question; however, it should open a discussion and give you an idea of their understanding in terms of current research.)


In this lesson, students will write a feature article on the Human Genome Project (which will ultimately be used as the evaluation of the lesson). In the Development, students will research and gather information to use in their articles.

Distribute the student sheet, The Human Genome Project. This activity sheet guides students to independently research and write their articles. Direct students to the Cracking the Genetic Code student esheet, which provides them with links to the online resources used in this lesson.

As you'll see, the following resources are provided on the esheet:


As described on the student sheet, feature articles should address the following:

  • The human genome, its history, and its development.
  • How the human genome project is the key to understanding our species as well as others.
  • The degree of kinship between organisms or species that is estimated from the similarity of their DNA sequences. Examples are worms and chimps, or other humans.
  • How DNA sequences can show us that we share common ancestors with other organisms.
  • How the Human Genome Project is affecting medicine.
  • What does it hold for the future?


At the Issues and Bioethics section of the Access Excellence website, there are some articles listed under Animal Genome Projects. Though they may repeat some information students have learned in this lesson, they will also add new information to help broaden their understanding of the project. Recommended readings include, but are not limited to:

Throughout this lesson, students have inevitably heard references to how the HGP will help us understand genetic disorders. To guide students in understanding this area of study, the Genetic Science Learning Center has a lesson on genetic disorders and how they occur. Students should start at What are Genetic Disorders?

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Lesson Details

Grades Themes Type Project 2061 Benchmarks