Transcript GM food
Genetically modified food (GM food) Lesson 1, 2: Introduction of the GM food Genetically modified food (GM food) In several thousands of years ago, people started to develop agricultural methods to improve plant quality and achieve better crop yield. The concept of the GM food is originated from the traditional cross-breeding. Both of the methods hopefully can improve the characteristic of agricultural products. Figure of the advancement in methods of agricultural products improvement 1850s – Cross pollination changed the characteristics of plants 1930s – Hybridisation became popularised 1975 – Cell fusion combined plant cells 1985 – DNA techniques drove plant modification into the gene level The major weaknesses of traditional methods • Traditional breeding usually involves random transfer of thousands of genes at one time to obtain the desired characteristics • The process is slow and unpredictable GM method and traditional method • The purposes of the GM method is boosting or weakening certain characteristics in a certain type of organism • We can control organism’s characteristics through genetically modification • The GM method is more accurate and efficient to control the organism’s characteristics than traditional method The development of GM food •The GM food developed in the 90s •In 1983, the first transgenic plant of the world, a tobacco plant resistant to an antibiotic, appeared. •In 1994, the first series of transgenic tomatoes with delayed maturation was introduced to the US market. Common examples of GM food Crops New characters from genetically engineering Oilseed rape Improved quality of oil products, antiherbicidal ability, new hybridity species from cross-breeding Maize (corn) Anti-pest,anti-herbicidal Potato Tomato Improved starch quality, anti-pest, anti-diseases, the process needed for improving and processing Delayed maturation period, the process needed for improving and processing Common examples of GM food Crops New characters from genetically engineering Wheat Improved starch quality and anti-diseases Sugar beet Improved starch quality, anti-diseases and herbicides Apple Anti-herbicides and delayed the maturation period Field vegetables Anti-pests,new species derived from hybridity Some main causes of developing the GM food Improve the characteristics of food – included yields, anti-pest and anti-herbicide species Crops with new qualities can be obtained – e.g. an improved nutritional status, better favors, easier to process or use of lesser amount of additives. Improvement of our environment – reduce the use of insecticides or herbicides for pest control of crops. Improving processing characteristics so as to reduce wastage and costs. Genetically engineered agricultures products Lesson 3, 4: the production techniques for the GM food Basic concepts • Genes are hereditary materials. • Genes are composed of Deoxyribose Nucleic Acid (DNA). • DNA is in every cell of your body. It contains the information needed to construct and operate a human body. • The cell of each plant or animal contains more than ten millions of genes • Genes carry biological information necessary to produce a protein(s) that determines the characteristics of an organism. • Proteins are major cell structures that operate most of the functions for human body to live. • Protein is a polymer synthesized from units of amino acids. DNA sequence is the genetic code Continually lengthening protein chain The purpose of genetically modification is using recombinant DNA to enhance or eliminate certain characteristics of certain organisms. We can control the characteristics of organisms through modifying genes. Examples of Genetically modification techniques 1) Ballistic impregnation: It involves sticking the genes on gold particles and hit on the plant cell. Some plant cells would take up the genes from the gold particles and then regrow. 2) Use of soil bacteria as a go-between: The soil bacteria Agrobacterium can change the genetic material of plant cells so that outgrowths are formed on the plant. The desired genes transferred to this bacteria is then incorporated into plant cells for producing the desired genetic characteristics. Examples of GM food: Tomatoes with delayed maturation period How to produce genetically modified crops? Genetically modified corns (anti-pest) 1. Bacillus thuringienesis is a bacterium that can produce a natural pesticide called Bt protein. The gene coded the anti-pest proteins 2. The gene coded for the Bt protein is isolated from the bacterium. 3. The isolated gene is then combined with a plasmid to form a recombinant DNA by using recombinant DNA techniques. Recombinant DNA 4. The recombinant DNA is put into another species of bacteria for producing more recombinant DNA. 5. Transfer the recombinant DNA in another bacterial species to produce more recombinant genes. 6. The bacteria is incubated with plant cell and the recombinant DNA will be transferred from bacteria cells to plant cells. 7. The plant cell develops to a plantlet. 8. Finally, The new plant is tested for the presence of the Bt protein. A genetically modified plant can be successfully created if the testing is confirmative GM crop The controversy of the GM food Opposing!! Lesson 5, 6: Supporting!! The contrversy of the GM food “ GM crops can improve the nutritional value, the taste and the crop yields. The amount of pesticides used can also be decreased which prevents environmental pollution to the natural environment.” Supporters “ GM crops can solve the problem of the Food Crisis due to the growth in population in the future.” Supporters “The developmental history of GM crops is too short. It has not undergone sufficient tests, which may be harmful to human health and ecological environment. ” Opponents “ There is no so-called ‘the Food Crisis’ in the world. The problem for us to concern is ‘wasting of food’ and ‘uneven distribution of food’. GM crops would only be bring profits to biotechnology companies and agricultural businesses.” Opponents The GM food Issue Case: GM (anti-pest) corn Starlink Lesson 5,6: The controversy of the GM food In 1997, a company named Plant Genetic Systems (now named Aventis) registered a GM anti-pest corn (Starlink) at EPA（The Environmental Protection Association of the United States）. EPA in the US only approved the corn for animal feeds at that time, as the conclusion on whether Starlink would cause human allergy has not been confirmed yet. EPA in the US has requested Aventis to notify the farmers to prevent mixing Starlink with human food. Lesson 5,6: The controversy of the GM food 2 years later, it is revealed that processed food of some popular brands contained compositions of Starlink and initiate a global retrieving action. More than 300 types of products composed of corns are involved. Meanwhile, some consumers have allergic responses after taking food containing Starlink. Some peasants also sue the Aventis as Starlink is mixed in the composition of their seeds. Then the Aventis made compensation settlement with 17 states in the US, the amount was between 100 million to one billion dollars. Lesson 5,6: The controversy of the GM food The GM food Issue Questions for self-reflection: Through understanding the viewpoints of supporters and opponents, and studying some cases, what is your opinion about the issue? What are your suggestions on establishing safety measures on the GM food?