Genetic Engineering SE (Completed) Answer Key

Student Exploration: Genetic Engineering Vocabulary: callus, exon, genetic engineering, genetically modified organism, genome, green fluorescent protein (GFP), herbicide, insecticide, intron, promoter, transcription, transformation Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. What are some things that can damage a farmer’s crops? insects. As well as birds and other small mammals 2. Bacteria and different What can farmers do to protect their crops? They may use sprays and in different locations, they use indoor farming as it’s becoming very popular although it is a bit more expensive Gizmo Warm-up Many farmers use chemical herbicides to kill weeds and insecticides to kill insects. Using genetic engineering, scientists have developed ways to resist harmful crop pests. In the Genetic Engineering Gizmo, you will use genetic engineering techniques to create genetically modified corn. Check that Task 1 is selected. The Gizmo shows petri dishes that contain different strains of bacteria (white dots) and caterpillars (Lepidoptera sp. larvae). In the first challenge, your goal is to find bacteria that produce toxins that kill the caterpillars. Click Play ( ). 1. What do you observe? to survive. A small amount of the caterpillars died while most where able 2. Which strains of bacteria were able to kill Lepidoptera sp. larvae? Were some more effective than others? Explain. meaning it affected some a lot more than others. Strains 4,5,8 and 10 Other caterpillars were killed off Some bacteria are able to produce a toxin that kills Lepidoptera sp. larvae. Find out which gene is responsible for this toxin in the next step. Activity A: Caterpillarresistant corn Get the Gizmo ready:  Click Reset ( ) and check that Task 1 is selected in the dropdown menu. Introduction: Lepidoptera sp. larvae (caterpillars) eat corn kernels, leaves, and stalks. In this activity, use genetic engineering techniques to create a corn plant that is resistant to caterpillars. Question: How can we produce corn that is resistant to Lepidoptera sp. larvae? 1. Observe: Click Play. Select one of the strains of bacteria harmful to larvae (by clicking on the plate). Which strain did you select? The 2 and 4 strains got affected too much and died 2. Investigate: Click Continue. The screen now shows the genome, or set of genes, of the selected bacteria. One of these genes produces the protein that kills the caterpillars. You will test each gene by adding it to the genome of a bacteria that does not kill caterpillars. This process is called transformation. Drag three genes into the Petri dishes at lower right. These genes are now inserted into the genomes of the sensitive bacteria in the plates. Press Play. If none of those genes help to kill the caterpillars, click Reset and try three other genes. When you find a gene that kills the caterpillars, click on the Petri dish to select the gene that confers resistance. Which gene did you select? Gene F In reality, finding a gene with a desired trait is much less common. Scientists search through many more bacterial strains and potential genes to find the traits they are looking for. 3. Observe: Click Continue. Promoters are regions of DNA that initiate the transcription of a gene. Some promoters only work in specific types of cells, such as leaf cells or root cells. To determine which cells of a corn plant a promoter works in, four promoters have been attached to the Green Fluorescent Protein (GFP) gene. Each promoter-GFP gene has been inserted into a corn plant. Select Lights off to see the parts of each plant glow green and fill in the table below. Promoter Glowing plant part(s) Promoter Glowing plant part(s) 1 Roots and leaves 3 Roots 2 Leaves 4 Leaves Which promoter is active in only the leaves? 1 & 3__ In the whole plant? 1____ Select the promoter you would like to use by clicking on a plant, and then click Continue. (Activity A continued on next page) Activity A (continued from previous page) 4. Choose: The resistance gene that was chosen in step 2 was attached to the promoter chosen in step 3, and the new DNA was inserted into five calluses. A callus is a group of cells that will incorporate the new gene into their genome and grow into a mature corn plant. In each genome, genes are shown as green bars. Each gene contains light green exons, or sections that code for proteins, and medium green introns, which do not code for proteins. The dark green bars represent promoters and the red bars represent gene termination sites. Use the left and right arrow buttons to observe where the new gene (blue bar) was inserted into each of the corn calluses genomes. Problems can occur if the new gene is inserted into the middle of an existing corn gene (green bar). In which calluses did the new gene insert inside an existing corn gene? in 1, 2, 3, 4, and 5. It was placed Select one of the corn calluses that do not disrupt an existing corn gene and click Continue. 5. Experiment: On the left is a control plant that does not contain any new genes. On the right is the transformed plant you created. Click Play. When the plant has finished growing, click on each of the circles to observe the leaves, cobs, and roots of each plant. A. Did the transformed plant grow into a healthy mature plant? Yes If not, you may have chosen a bad callus. (Click Back to try a different callus.) B. Click Reset and select Add Lepidoptera sp. larvae for each plant. Click Play. What do you observe? One was infected with insects the other one was fine C. Compare the up-close views. How do the roots, leaves, and cobs compare? The caterpillars were found in the plant but the control plant was completely fine D. Select Show statistics. How did the results for the transformed plant differ from the control plant? Less larva is better for the corn E. Click Submit for review. Was your plant resistant to Lepidoptera? Yes, it was. If not, click Back or Start again. Be sure to choose genes that kill bacteria and a promoter that protects the corn cobs, leaves, and stalks. Activity B: Beetle grubresistant corn Get the Gizmo ready:  Click Start again to reset the Gizmo.  Select Task 2 in the dropdown menu. Introduction: Coleoptera sp. larvae are immature beetles. They feed on corn plant roots. Your goal in this challenge is to create corn that is resistant to Coleoptera sp. larvae. Question: How can we produce corn that is resistant to Coleoptera sp. larvae? 1. Investigate: Using the Gizmo, select a bacterial strain that kills Coleoptera and determine the gene that will be used to develop resistance in the corn. Which choices did you make? Bacterial strain: __1__ Gene: _A__ Click Continue to move on to the “Choose promoter” step. 2. Hypothesize: Turn the room lights off. Beetle larvae attack the roots of corn plants. Based on this, which promoters do you think would be effective against beetles? 1 Explain your reasoning. I believe one will be the best option as it is the healthiest and cleanest. As well as one of the strongest. 3. Apply: Knowing that the new corn strain will be eaten by humans, which promoter might be safer to use, and why? 3, as only its roots are glowing, which means there's nothing in the leaves Select this promoter and click Continue. 4. Observe: Select a corn callus that you think will work and click Continue. On the next screen, add Coleoptera sp. larvae to each plant and click Play. The control plant A. Describe the control plant and the transformed plant. seems fine. On the other hand, the transformed plant looked dead and brown B. Select Show statistics and Submit for review. Is the experimental plant resistant to Coleoptera sp. larvae? The best population transformed is 4. Coen yield control is 95 and transformed is 5 (Activity B continued on next page) Activity B (continued from previous page) 5. Explore: Click Back and select a corn callus in which the new gene (blue bar) is inserted in the middle of an existing gene (green bar). A. Click Continue. Grow the experimental plant with and without larvae. What do you observe? The plant still looks weak and brown and the roots of the plant. B. Click Back and choose another callus in which an existing gene is disrupted. What do you observe? Callus two look pretty healthy on both sides Note that these are dramatic examples of mutations. Complex organisms often have many genes that can perform similar functions, so disrupting one gene may not cause a noticeable change to the phenotype of the plant. 6. Explore: Click the Back button twice until the Choose promoter step is shown. Use the Gizmo to test the effectiveness of each promoter. Which promoters were effective in creating beetle-resistant corn, and why? because have brown corn 2, 3, 4 7. Explore: Click Start again. This time, choose a bacterial strain in step 1 that only kills some of the larvae. Grow the experimental plant in the presence and absence of larvae. How does this plant compare to the plant you created in part 4 of this activity? __This section's brown corn was evolved 8. Think and discuss: What are some of the possible benefits of creating insect-resistant corn, and what are some of the possible drawbacks? If possible, discuss your answer with your classmates and teacher. This makes the corns thrive and have a more likely hood of surviving to adult life and can be sold by not letting Pastides and insects. Although this is good the only drawback is that they could potentially be sold at a higher price as the process does take a bit of time Activity C: Herbicideresistant corn Get the Gizmo ready:  Click Start again to reset the Gizmo.  Select Task 3 in the dropdown menu. Introduction: Weeds are wild plants that compete with crops for resources. Farmers kill weeds using herbicides, but corn plants may also be damaged by herbicides. Herbicides affect the roots, stalks, leaves, and cobs of corn plants. Question: How can we produce a corn plant resistant to herbicide? 1. Observe: Bacterial colonies are being grown in Petri dishes. The white disks on each dish have been soaked in an herbicide. Click Play. Describe what happens to the bacteria in the Petri dishes. Which strains of bacteria are not affected by the herbicide? Both 3 and 9 2. Observe: Choose a bacterial strain that is resistant to herbicide, find the gene that is responsible for the resistance, choose a promoter, and transform a corn plant. Observe the control and experimental plants in the presence and absence of herbicide. When you have created an herbicide-resistant plant, fill in your choices below. (Note: you may need to try a few promoters before finding the correct one.) A. Which bacterial strain did you choose? Bacteria 2 Which gene did you choose? Gene A Which promoter did you choose? Which callus did you choose? 3_____ __1 B. Describe the control and experimental plants. The transformed plant produced smaller corn than the plant that wisent changed C. Select Show statistics. How do the results from the transformed plant differ from the control plant? Explain. The only difference would be size__ (Activity C continued on next page) Activity C (continued from previous page) 3. Experiment: Go back two steps and experiment with different promoters. Can any of the other promoters be used to create a resistant corn plant? Yes___ Why or why not? Promoter 2, callus 1 gives a 2 % difference between control and transformed plant. The control plan led to up to 95% cornfield and transform was 93% 4. Analyze: What are some of the benefits of growing herbicide-resistant corn? It helps clean the corn and protect it from bacteria and insects 5. Analyze: Are there any possible drawbacks to having an herbicide-resistant corn plant? The chemicals in herbicide could lead to a possible reaction to human beings consuming the corn. 6. Think and discuss: Herbicides and insecticides can be bad for the environment. Insecticides could harm beneficial insects like bees, and both herbicides and insecticides can contaminate nearby rivers and streams. A. What are some of the possible environmental benefits of GM crops? More crops in the markets and all in all boosting the economy. As well as its not processed and still extremely healthy. B. What are some of the possible environmental problems that can be caused by GM crops? Allergies and toxic herbicides C. What are some of the potential risks to humans and animals that eat GM crops? People may tend to have allergic reactions or dislike the flavor it gives off as well as other health risk