Directions for teachers: After students have had a chance to read “Ban on gene-edited babies proposed,” review what students know about some related science concepts including DNA, variability and heritability. You can lead a class discussion using the questions provided. After reviewing basic concepts, have students draw on their past knowledge or search the Science News archive and other resources to come up with examples of how genetic engineering has been used in the past.
DNA: Ask students to recall the structure of DNA and define what genes are. They can also discuss how DNA structure determines the structure and function of proteins.
Genetic variability and modification: Ask students to define genetic variability and discuss how changes in DNA are introduced through normal mating processes as well as mutations caused by other factors. Ask students to recall the history of humans’ role in genetic modification, from selective breeding to genetic engineering.
Heritability: Ask students to discuss what makes some changes in DNA heritable, with a focus on germ line (or sex) cells. Review how these DNA changes get passed down through generations, and how the changes can affect people’s lives.
Genetic engineering applications
1. Name one example of how genetic engineering has been used to fight or treat disease. What is the disease? What information can you find about what DNA has been modified and how? What is the effect of that modification? Is it a heritable change?
Students might mention that scientists are experimenting with genetic engineering in the lab to control malaria-carrying mosquitoes. Researchers use the gene-editing tool CRISPR/Cas9 to engineer bits of DNA into a gene drive. A gene drive inserts itself into an organism and spreads quickly through a population, forever altering offspring or preventing offspring from being born.
Students may also say something about using genetic engineering to modify immune cells to treat diseases like leukemia and lung cancer. Or they might mention how scientists use genetic engineering to figure out how to make medicines more efficiently. Recombinant DNA technology, for example, was used to insert insulin-making genes into bacteria. The modified bacteria could then churn out large quantities of the drug.
2. Name one example of how genetic engineering has been used to support or improve agriculture. What organism was modified? What information can you find about what DNA has been modified and how? What is the effect of that modification? Is it a heritable change?
Students could mention using genetic engineering to make certain crops resistant to things like droughts, floods, pests or extreme temperatures. Genetic engineering could also be used to increase crop yields.
Students may also discuss how genetic engineering is used on animals that people eat. One example is salmon that were given a gene from another fish to make the salmon grow bigger faster. Those salmon were the first genetically engineered animals cleared for human consumption anywhere in the world.
3. Name one example of how genetic engineering has been used for basic research. What organism was modified? What can you find about what DNA has been modified and how? What is the effect of that modification? Is it a heritable change?
Students might say that genetic engineering is used to manipulate lab animals. For instance, researchers have engineered breeds of mice that mimic symptoms of human diseases like Alzheimer’s. Scientists experiment with these animals in an attempt to unravel the causes and test potential treatments for the disease. Other researchers are engineering more exotic critters, like cephalopods, to turn them into lab animals. Cephalopods could be used to study motion, camouflage and neural systems. Such research could have applications for robotics, computing, prosthetics and more.
Students could discuss how genetic engineering can be used to explore which genes are essential for life. For instance, researchers created a bacterium that has the smallest genome needed for free living, with just 473 genes. Students might also talk about how researchers are using gene editing to store data within DNA. Scientists have encoded audio recordings, short movies, poetry and even entire books into bacterial DNA.