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Semelhante a The History of Biotechnology
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The History of Biotechnology
- 1. Unit 1, Lesson 2 AOHS Biotechnology The History of Biotechnology Copyright © 2014‒2016 NAF. All rights reserved.
- 2. Biotechnology uses our understanding of biology to solve problems Can you name some products of biotechnology? Biotechnology is the manipulation of living organisms or their components to produce useful products.
- 3. Humans have used biotechnology for millennia Breeding animals and developing crops was the earliest biotechnology, dating back over 9,000 years. Why would people want to breed animals and plants? How could they do that without knowing about DNA?
- 4. Modern domestic tomato Selective breeding alters plants and animals Over thousands of years, farmers used selective breeding (choosing which individuals get to reproduce) to select for desirable traits in plants and animals. Wild tomatoes
- 5. Biotechnology has transformed the food we eat
- 6. This ancient wooden model shows Egyptian people in the process of making beer, a practice mentioned in some of the earliest written history. Beer making dates back to the early Neolithic period or 9500 BCE when cereal was first farmed. Ancient civilizations used biotechnology tools, such as microbes, to alter the flavor and properties of food
- 7. Modern biotechnology has roots in the 1800s and 1900s Biologists began to understand the mechanisms of life in the 1800s. In 1831, botanist Robert Brown described the cell nucleus. What do we call organisms that lack cell nuclei?
- 8. Agar is a good medium for growing bacteria Can you name any common foods that contain agar? In 1881, Walther Hesse discovered agar as a medium for culturing bacteria when he asked his wife, Franny, what kept jelly solid in summer. Franny and Walther Hesse A petri dish with agar and bacteria
- 9. Mendel’s pea-plant experiments help explain inheritance Do you remember Mendel’s experiments from your biology class? Can you explain dominant and recessive alleles? In 1866, Gregor Mendel published a report on his pea- plant breeding experiments and laws of inheritance. But Mendel’s report was overlooked, perhaps because it was not written very clearly. Mendel died in 1884, never recognized for his discoveries. It was only in 1900 that Mendel’s work was rediscovered and understood.
- 10. Animals were first cloned over 100 years ago If a sea urchin was cloned in 1885, why did it take over 100 years for a sheep to be cloned? Why are clones useful in research? In 1885, Hans Driesch cloned the first animal, a sea urchin. In 1996, the first mammal to be cloned was a sheep named Dolly.
- 11. In 1928, Alexander Fleming discovered penicillin by noticing a mold that kills bacteria Have you ever been prescribed penicillin, or a related antibiotic like ampicillin or amoxicillin, for an infection? Alexander Fleming A white penicillium mold in the middle of an agar dish filled with bacteria. Notice there are no bacteria near the mold.
- 12. In 1953, Watson and Crick determined the structure of DNA What do you remember from biology class about the structure of DNA? Why is the structure of DNA important? Jim Watson (left) and Francis Crick (right) with their model of DNA
- 13. Biotechnology is both ancient and modern What do you remember about important events in biotechnology from these images?
Notas do Editor
- Image retrieved from http://commons.wikimedia.org/wiki/File:EMS-89615-Rosecrucian-Egyptian-BeerMaking.jpg Photographer E. Michael Smith Chiefio. Retrieved April 18, 2014.
- Image on left retrieved from http://en.wikipedia.org/wiki/File:Robert_Brown_%28botanist%29.jpg on December 27, 2013. Image courtesy of Maull & Polyblank. The image is in public domain in the US because its copyright has expired.
- Image on left retrieved from http://ihm.nlm.nih.gov/luna/servlet/view/all/what/Portraits on December 27, 2013. Image on right retrieved from https://visualsonline.cancer.gov/details.cfm?imageid=2230. Image courtesy of Bill Branson (photographer).
- Gregor Mendel’s experiments with pea plants led him to propose the idea of what we now call genes: microscopic internal units of information, one from each parent, that produce offspring with a mix of parental traits but which are passed on without blending. A different version of a gene, called an allele, comes from each parent. If an allele is dominant, its corresponding trait will always be expressed. A recessive allele will be expressed only when both alleles present are recessive. This discovery was important because it suggested how information might be passed from one generation to the next. Before Mendel, people realized that offspring resembled their parents but lacked any understanding of why or how that happened. They didn’t have the idea of genes. Mendel’s discoveries are recognized today as some of the most important ever made in biology. But Mendel’s work was overlooked at first. We can’t be sure of all the reasons for this, but one possibility is that Mendel was not the best writer. The reports of his research that he published are difficult to understand. It was only in 1900 that scientists rediscovered Mendel’s reports and recognized their significance. This is a powerful example of why it is important to write good lab reports that other people can understand. Even making a huge discovery, like Mendel did, is not enough. You have to be able to communicate your research findings to other people.
- When you hear the term cloning, you probably think of modern biotechnology, or maybe science fiction movies about cloned humans. But cloning, the production of two completely identical organisms, isn’t new. Hans Driesch, who specialized in the study of embryos, cloned a sea urchin over a century ago. His methods for cloning experiments were not sophisticated by modern standards. For example, he cloned a sea urchin by simply shaking the embryo until it split in two. But Hans Driesch’s experiments laid the foundation for more advanced methods for manipulating and studying embryos. An important landmark in cloning came over a century after Driesch’s work, when in 1996 Dolly the sheep became the first mammal to be cloned. Mammal embryos are more complicated and delicate than the embryos of species like sea urchins, so much more advanced techniques were required. Being able to produce genetically identical organisms is useful in research. For example, having genetically identical individuals allows you to test the impact of different environmental conditions on their growth and development. Image on left retrieved from http://upload.wikimedia.org/wikipedia/en/b/ba/Driesch.jpg on December 27, 2013. Image on right retrieved from http://upload.wikimedia.org/wikipedia/commons/f/f4/Strongylocentrotus_purpuratus_1.jpg and reproduced here under the terms of the Creative Commons Attribution 3.0 Unported license (http://creativecommons.org/licenses/by/3.0/deed.en). Image courtesy of Kirt L. Onthank.
- Image on left retrieved from http://upload.wikimedia.org/wikipedia/commons/3/3d/Alexander_Fleming_3.jpg Image on right from http://archive.bio.ed.ac.uk/jdeacon/microbes/penicill.htm courtesy of Jim Deacon.
- Image retrieved from http://education-portal.com/cimages/multimages/16/WatsonCrickDNA.jpg on December 27, 2013 and reproduced here under fair-use guidelines of Title 17, US Code. Photo taken by Antony Barrington-Brown.
- Image credits: See previous slides.