PLS 12 SAS 12 Final Study Guide
PLS 12 SAS 12 Final Study Guide SAS 12
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This 6 page Study Guide was uploaded by Lauren Murvihill on Saturday March 12, 2016. The Study Guide belongs to SAS 12 at University of California - Davis taught by Professor Drakakaki in Winter 2016. Since its upload, it has received 49 views. For similar materials see Plants and Society in Plant Science at University of California - Davis.
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Date Created: 03/12/16
SAS12/PLS12 Final Study Guide Who was Norman Borlaug? Norman Borlaug was the father of the Green Revolution. As an American scientist interested in agriculture, Borlaug began conducting research in Mexico in the 1940s and developed new, diseaseresistant, and highyielding varieties of wheat. This allowed Mexico to produce more wheat than it needed, giving it the opportunity to export the crop by the 1960s. He also helped other countries develop their agriculture in this same manner. What happened during the Green Revolution? During the Green Revolution, agricultural production improved worldwide. Mexico became an exporter of wheat instead of an importer. In Pakistan and India, wheat yield doubled from 1965 1970. Farming practices were improved, and gene banks were established. The Green Revolution caused massive improvements in food security worldwide, but we still have a lot to go to fully solve the issue. How was agriculture affected by Green Revolution? Agriculture production improved greatly due to the Green Revolution. More crops were grown, food security increased, and many countries began exporting crops rather than importing them. The Green Revolution paved the way for further advancements in agriculture in the future. What are main characteristics of a varietal improvement? What are we looking for in crops as a society? A varietal improvement has the characteristics of genetic variability, adaptable, reliable, large yields, short growth duration, resistance to biotic stresses, and tolerance to abiotic stresses. As a society, we are looking for crops that have all of the characteristics of a varietal improvement so that we can help fix the food security problem. How did the world’s population grow exponentially? What were the main causes of this tremendous growth? The Green Revolution is directly responsible for the exponential growth of the world’s populations. With much more food available for consumption, larger populations of people could be supported. What is carrying capacity? What are the relevant theories of carrying capacity? We have Malthusian as well as many other divergent views ponder the implications and realities of these theories. arrying capacity is the maximum population that can be supported by natural resources for present and future generations and the maximum rate of resource consumption and waste discharge that can be sustained. The relevant theories of carrying capacity is Neo Malthusianism and NonMalthusianism. NeoMalthusianism is divided into two parts: Ecological Malthusians and Protectionist Malthusians. Ecological Malthusians state that population growth undermines the natural resource base. Protectionist Malthusians observe the consequences of population growth on jobs, service, education, etc. NonMalthusians believe that due to modern technology, human population will not exceed the amount of resources necessary for everyone’s survival. *What are the classic stages of demographic transition? Demographic transition is accompanied by age transition. If the birth rate and death rate change, this causes changes in demographics. How does this apply to a developed versus a developing country? In a developed country, the birth rate and death rate do not change much. In a developing country, the birth rate and death rate fluctuate. What is the Greenhouse effect? What are its predicted impacts on food security? The Greenhouse Effect is the process by which the Earth’s surface heats up to temperatures above normal due to the trapping of heat in the form of infrared. There are several predicted impacts of the Greenhouse Effect on food security: the “wheat belt” will not be able to produce wheat anymore; corn production the US will drop; wheat production will increase in Canada; irrigation schemes will be impacted due to changing rainfall patterns; the sea level will rise, causing a drop in the production of certain crops such as rice. What are the current limits of agriculture? Which environmental factors (temperature, water, light) affect crop production and our asymptotes of change as a result? Climate change and global warming place limits on agriculture due to the environments these forces create. Additionally, the amount of arable land available is decreasing, which puts more limits on agriculture. Water limits agriculture because of there is too much it drowns crops and if there is too little it starves crops. Even though light seems abundant, the increase in greenhouse gases has made it more difficult for crops to absorb light, limiting agriculture. Temperature affects crop production because crops need a certain range of temperature in order to thrive; if this is not met, crop production decreases. What are the effects of global warming on agriculture? Global warming causes the things that plants need to thrive to change, resulting in lower crop yields. It creates temperatures that are too hot or too cold for plants to grow, it causes severe flooding of crops in some parts of the planet and severe drought in others, and it makes it difficult for plants to absorb light due to the greenhouse gases that are produced. What are different methods of pest control management? First off, consider the different types of pests. There are several different kinds of pests that impose a variety of damage upon crops. These pests include beetles, worms, nematodes, parasites, pathogens, and others. Targetspecific and lowtoxicity pesticides, natural enemies that eat the pests, pheromones, and genetic resistance are different methods of pest control management. What are the main principles of IPM? What methods are used, how are they combined? How do these management techniques affect the potential market for these crops? Integrated Pest Management (IPM) sets action thresholds, monitors and identifies pests, prevents certain practices, and controls pests biologically, chemically, with pheromones, genetic resistance, or targetspecific and lowtoxicity pesticides. This allows farmers to grow crops that would normally be susceptible to pests, which improves the market for these crops. What is biological control? Examples? Biological control is the use of predators, parasites, and pathogens to manage pests. This could be introducing birds into a field of crops to eat the grasshoppers that are affect crops. What is precision agriculture? Precision agriculture is a management strategy that employs detailed, sitespecific information to precisely manage production inputs. What are biofuels? What different types of biofuels do you know? Biofuels are energy sources that are not as harmful to the environment as fossil fuels and petroleum are. There are many different types of biofuels that are broken up into generations such as ethanol, nonfood feedstocks, hydrocarbons, algae, and geneticallyengineered crops. What is the effect of lignin in biofuel production? What challenges does this present? With current technologies, can we utilize high lignin materials efficiently? Cellulose is embedded within lignin, which makes it difficult for scientists to extract cellulose from the plant to make biofuels. If scientists were to prevent plants from producing lignin, plants would not be able to grow upward and erect. With current technologies, we can use highlignin materials for energy, but not efficiently. Give two attributes of an ideal biomass crop. An ideal biomass crop is uses C4 photosynthesis and recycles nutrients to its roots. Describe 3 steps in biofuel production; what is pretreatment, what is enzymatic hydrolysis, and what is achieved in each step? Pretreatment increases digestibility of residual cellulose and hemicellulose. It is needed to liberate cellulose from the lignin seal and its crystalline structure so that it can be accessible for hydrolysis. Hydrolysis liberates sugars from biomass by using cellulases to degrade cellulose. The result of these two steps is cellulose, hemicellulose, and pectin. What are the products from enzymatic hydrolysis? The products of enzymatic hydrolysis is cellulose, hemicellulose, and pectin. What is described by the process of fermentation during biofuels production? Fermentation occurs in the absence of oxygen. It is the conversion of sugars into liquid fuel and other products such as ethanol. What are advanced biofuels? Advanced biofuels are any biofuels that are second generation or higher. How can you use biotechnology and current molecular and genomic approaches in biofuel industry? Biotechnology and current molecular and genomic approaches can be used in the biofuel energy to create crops that yield the most energy while using the fewest resources. For example, scientists can create crops that are droughtresistant and can grow on nonarable land but is high in cellulose. These types of biofuels are called fourthgeneration biofuels. What are the controversies regarding biofuels? Biofuels are controversial because many believe that they will make the food security problem worse since many crops used for biofuels need to be grown on arable land. Additionally, many think that they might be expensive. What were the contributions of the following scientists in biology? Charles Darwin, Gregor Mendel, Watson and Crick. Charles Darwin wrote The Origin of Species and fathered the idea of natural selection. Gregor Mendel used pea plants to show how the inheritance of genes works. Watson and Crick identified the doublehelix structure of DNA using information from Rosalind Franklin. What were Mendel’s first three postulates? Mendel’s first three postulates are 1. segregation: each organism has two alleles for a gene that separate during meiosis so that each gamete gets one copy of the gene; 2. independent assortment: gene alleles segregate during meiosis independently of other genes; and 3. dominance: if one allele is dominant over the other, then the phenotype will display the effect of just the dominant allele. What characteristics (traits) were improved by plant breeding? Traits that were desirable for human use or consumption were improved by plant breeding. The result was plants with exaggerate plant parts such as larger seeds, fruits, leaves, stems, and roots. What are Mendel’s Laws? See “What were Mendel’s first three postulates?” What the following terms mean: Homozygote, Heterozygote, Genotype, Phenotype. Homozygote: an individual which contains only one allele at the allelic pair. Heterozygote: an individual which contains one of each member of the gene pair. Genotype: the genetic constitution of an individual organism. Phenotype: the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment. What is a gene pool? A gene pool is the stock of different genes in an interbreeding population. Distinguish between the four gene pools used by plant breeders as potential sources of novel genetic variation for crop improvement. GP1: crop and wild relative; crosses are easy, progeny are viable and fertile. GP2: species can cross with GP1; lower success rate; progeny less viable and fertile. GP3: species crossed with great difficulty; tissue culture/embryo rescue; progeny of limited viability and fertility. GP4: species cannot be crossed with GP1. What are different breeding methods used to introduce new or improved traits into crops? Different breeding methods are clones, pure lines, openpollinated cultivars, and hybrids. Give an example of a crop that is primarily grown as a hybrid in the United States. Corn, rice, and cucumber. *Why must plant breeders often conduct several generations of backcrosses to the cultivated crop parent in order to introduce a single desirable trait that is controlled by one or two genes from a wild relative? They may need to do this in order to create progeny that have desirable traits. What is the difference between inbreeding depression and heterosis? Inbreeding depression is the reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals. It is often the result of population bottleneck. Heterosis is the increased vigor or productivity of a plant compared to its parents. What are the characteristics of hybrid crops? Hybrid crops exhibit heterosis but do not breed true. They have higher yield, greater uniformity, and broader environmental adaptability than their parents. What are the limitations of hybrid varieties? A limitation is that the seeds must be produced again each year because the genes in the F1 hybrid segregate in the next generation, losing most of the plant’s original advantages. What genetically engineered (transgenic) crops grown in the United States do you know of? Tomatoes and soybeans. What is a ‘transgenic’ crop? A transgenic crop is one that has been genetically engineered to have new characteristics. Distinguish between output and input crop traits that can be improved using biotechnology. Give examples of each. Input crop traits are modifications that affect the ability to produce the crop such as ease of production, efficiency of production, and cost of production. Output crop traits are modifications that affect the crop itself such as composition, quality, and value. Biotechnology that improves on these factors are beneficial. Give examples of biotic stresses. Biotic stresses are pathogens, bacteria, viruses, and insects. List management practices used to control weeds in food crops that are not dependent on genetic modification. Physical barriers such as wood chips and plastic can control weeds. Tillage, hoeing, crop rotation, mulches, and burning can also help. Cover crops can control weeds because they grow where weeds would grow. Herbicides are also used. Describe mechanisms of engineering herbicide resistance give an example. Modern herbicides are highly specific, generally targeting enzymes or processes specific to plant metabolism. Engineering resistance involves the introduction of a gene/genes that encodes for 1. a modified form of target enzyme that the herbicide cannot inactivate or 2. an enzyme that detoxifies the herbicide. Describe two benefits of herbicideresistant crops to farmers. Herbicideresistant crops are beneficial to farmers because they increase yields, reduce input costs, reduce herbicide use, reduce environmental impact, control weeds, create flexibility for crop rotations, create more precise agricultural practices, and reduce tillage. List two management practices used to control insect pests in food crops. Insecticides and Bt corn. What is Bt corn? How does it work? Bt corn is corn that has been genetically engineered to contain Bacillus thuringiensis, or Bt, a bacteria that has insecticidal properties. When consumed by a pest, Bt binds to receptors in the pest’s gut, causing the gut wall to break down, allowing spores and normal gut bacteria to enter the pest’s body. The pest then dies as spores and gut bacteria proliferate in the body. Bt crops have contributed significantly to improving worker safety in several countries around the world. How is worker safety improved by growing Bt crops? Worker safety is improved by growing Bt crops because it reduces the number of pests that could harm workers and eliminates the need for toxic insecticides that negatively impact worker safety. *How can you generate transgenic plants that express the transgene in specific tissues? What is the advantage of this approach? You can generate transgenic plants that express the transgene in specific tissues by inserting the gene in the part of the DNA that codes for a certain tissue. The advantage of this approach is that multiple new genes can be expressed in the plant instead of just one. Classes of organisms cause diseases of crop plants? Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, viruslike organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Biotechnology for output traits what are they? Give several examples. Output traits are modifications that affect crop composition, quality, and value, rather than the ability to produce the crop. This includes nutritional content, postharvest physiology improvement like shelf life, appearance, flavor, color, taste, and aroma. Why the “Golden Rice” was a difficult project both scientifically and culturally? How was it achieved scientifically? The Golden Rice project was difficult scientifically because many different genes had to be used in order to make the rice. There was a lot of trial and error that had to happen in order for the Golden Rice to be made into what it is today. The Golden Rice Project was even more difficult culturally because many people do not trust GMOs and therefore refuse to eat it. Some went to far as to prevent scientists from improving Golden Rice by destroying fields of it. Eventually, Golden Rice was achieved scientifically by taking the genes of a daffodil, some bacteria, and injecting beta carotene. What would be a potential humanitarian benefit of using Golden Rice? The potential humanitarian benefit of using Golden Rice is the ability to feed millions of people suffering from hunger and/or Vitamin A deficiency. It will help to prevent blindness and hunger in millions of people. Biotechnology beyond Agriculture – what are the different applications what are the human applications? Biotechnology can also be used for disease treatments, diagnostics, environmental cleanup, green chemistry, antibodies, biofuels, and vaccines. What are the advantages of plants for pharmaceutical production? They reduce costs, increase stability, and are safer to use. What are antibodies and vaccines? Antibodies are proteins produced by the body’s immune system when it detects harmful substances (antigens). Vaccines are a substance used to stimulate the production of antibodies and provide immunity against one or several diseases, prepared from the causative agent of a disease, its products, or a synthetic substitute, treated to act as an antigen without inducing the disease. List several applications of biotechnology for biofuels. Biotechnology can be used to make plants for biofuels that can survive in a variety of conditions. They can be engineered so that more energy can be extracted from them. Agencies regulating biotech crops – which ones do you know what are their functions? The US Department of Agriculture determines whether the crop is safe to grow. The Food and Drug Administration determines whether the crop is safe to eat. The Environmental Protection Agency regulates crops that have pesticidal properties. Why are some sectors of the general public concerned about the use of genetically improved (modified) products. They think that genetically modified products will harm human health. Safety data requirements for registration of biotech crops list 5. Product description, molecular characterization, toxicity studies, antibiotic resistance marker genes, and nutritional content.
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