Name___________________________________ Class: __________ Ms. Umali (2.08)-­‐ Genetic Engineering Date: __________ Aim: DO NOW: Read the text below and use it to answer questions 1-­‐3. For thousands of years we have produced new varieties of plants and animals. We did this by selectively breeding plants and animals for particular traits. To “breed” means to mate or reproduce. Selective breeding takes advantage of genetic variation occurring in nature. In other words, the great variety found in wild plants and animals makes selective breeding possible. Selecting breeding is often called artificial selection because rather than letting nature decide what animals breed, humans intervene. Humans use selective breeding to cross (or mate) organisms that have different traits to bring together the best of both organisms. The offspring made by such crosses are called hybrids. Selective breeding can also be used to create new varieties of plants. Many of these hybrid crosses mix the disease resistance of one plant with the food-­‐making ability of another. The results are new lines of plants that allow farmers to make more food. Selective breeding is also used to create some of our favorite pets! For example, a Labradoodle is a hybrid dog created by crossing the Labrador Retriever and the Poodle. Labrador Retriever Poodle Labradoodle 1. Based upon what you read, define selective breeding in a complete sentence _________________________________________________________________________________________
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_________________________________________________________________________________________ 2. Fill in the blank: Selective breeding is also referred to as ____________________________________. 3. The labradoodle is a product of selective breeding. Explain what this statement means. _________________________________________________________________________________________
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_________________________________________________________________________________________ Class notes: Genetic Engineering is… ________________________________________________________________________ ____________________________________________________________________________________________ Selective breeding is… ________________________________________________________________________ ____________________________________________________________________________________________ Why selective breeding is a form genetic engineering? ______________________________________________________________________________________
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______________________________________________________________________________________ Selective breeding results in advances in agriculture. Long before Europeans came to the New World, Native Americans had selectively bred teosinte (tee oh sin tee). Teosinte is a wild grass native to central Mexico. Teosinte was selectively bred to make corn. Corn is a far more productive and nutritious plant than teosinte. Corn is also now one of the world’s most important crops. Modern corn was selectively bred from teosinte at least 6000 years ago. Over time, the hard case around the kernel disappeared, which left the rows of soft kernels we enjoy today. The plant has also been bred to become larger and produce more. Explain the development of modern corn! Imagine you are sitting at the dinner table (maybe even tonight) and a giant bowl of corn is placed on the table. You say to the others at the table, “Did you know that corn wasn’t always like that?!” Your little sister says you’re weird and doesn’t believe you. Explain how modern corn developed from teosinte. In your response, be sure to identify and explain the process used. ____________________________________________________________________________________________
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____________________________________________________________________________________________ Independent Practice Directions: Use the information you learned today to answer each question. 1. Which is a breeding method used by humans to produce new varieties of plants and animals? (1) independent assortment (2) natural selection (3) artificial selection (4) crossing over 2. One variety of strawberry is resistant to a damaging fungus, but produces small fruit. Another strawberry variety produces large fruit, but is not resistant to the same fungus. The two desirable qualities may be combined in a new variety of strawberry plant by (1) cloning (2) asexual reproduction (3) direct harvesting (4) selective breeding 3. A new variety of tomato is better tasting and can be stored longer than other tomato varieties. This new tomato is produced by placing addition gene segments into the cells of the tomato plant. This process is known as (1) genetic engineering (2) selective breeding (3) natural selection (4) sexual reproduction 4. The illustration below traces the development of the corgi dog over several generations as a result of human activity. This is an example of the human activity called (1) mutation (2) genetic engineering (3) selective breeding (4) natural selection 5. A research team wants to cross two different varieties of corn to produce a single variety that has traits from both parents. This technique is an example of: (1) competition (2) natural selection (3) selective breeding (4) ecological succession 6. Selective breeding has been used to make certain breeds of horses for the purpose of racing. Describe why you think people would want to selectively breed horses. Be sure to mention particular traits that would be beneficial for race horses. Answer in complete sentences. ____________________________________________________________________________________________
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____________________________________________________________________________________________ 7. One variety of wheat is resistant to disease. Another variety contains more nutrients of benefit to humans. Explain how a new variety of wheat with disease resistance and high nutrient value could be developed. In your answer, be sure to: • identify one technique that could be used to combine disease resistance and high nutrient value in a new variety of wheat • describe how this technique would be carried out to produce a wheat plant with the desired characteristics ____________________________________________________________________________________________
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