Presentation on theme: "Food Production Macronutrients- carbohydrates, proteins and fats Micronutrients- vitamins (A, C, E) and minerals (iron, iodine, calcium) Chronic undernutrition:"— Presentation transcript:
Food Production Macronutrients- carbohydrates, proteins and fats Micronutrients- vitamins (A, C, E) and minerals (iron, iodine, calcium) Chronic undernutrition: not getting an adequate amount of calories Chronic malnutrition: deficiency of key nutrients Has been an improvement in the number of people facing chronic undernutrition around the world. But in developing world 1 in 6 people still suffer from chronic undernutrition.
Green Revolution (starting in 1950’s) Selectively bred crops (also know as artificial selection) with higher yields. Inorganic fertilizers Pesticides Genetically- engineered crops
Genetically Modified Organisms : Also known as Transgenic Organisms or Bioengineered Species A biotechnology technique that allow genes from different species to be inserted into an organisms genome. Example: Fish tomato Tomato with gene from flounder to reduce freezing. Was never commercially available
Gene splicing (joining two different pieces of DNA) relies on the use of restriction enzymes, which are natural occurring enzymes from bacteria whose function in bacteria is to cut up invading pieces of viral DNA. Most restriction enzymes cut DNA in a way that leaves single stranded DNA ends (sticky ends). Basics of Recombinant DNA Technology
The Process of Recombinant DNA 1.Both a vector such as a plasmid and a gene of interest are cut with the same restriction enzyme. 2.The complimentary sticky ends of the two different pieces of DNA allow them to be joined. DNA ligase forms bond. 3.Recombinant plasmid introduced into cell culture.
Examples of GMO crops o Golden Rice: beta carotene gene from daffodils inserted into rice plants. Beta carotene can be converted into Vitamin A in the body. o Round-up Ready (glyphosphate resistant): Gene for resistant to the herbicide is inserted to allow crops to be sprayed with the herbicide. o BT crops: Gene for natural insecticide from bacteria Bacillus thuringiensis is inserted into crops.
Genetically Modified Organisms Projected Advantages: Projected Disadvantages: Higher yields due to potential for improved characteristics such as resistance to insects, disease, frost etc. Irreversible and unpredictable ecological effects. New allergens in foods Improved quality of crop due to new characteristics: less spoilage etc. Increase in pesticide- resistant insects, herbicide- resistant weeds etc. Can harm beneficial insect Lower genetic diversity
Pesticide- general term for a substance that kills some type of unwanted pest. Types Insecticide Herbicide- kills weeds (plants) Fungicide- kills fungi (blight, mold, mildews and rusts)
Pesticides 1 st Generation Pesticides- natural chemicals (esp. from plants) 2 nd Generation Pesticides- starting with DDT in 1939 Broad-spectrum agent: Effective against a wide range of pests But also kill beneficial species. Chlorinated hydrocarbons: such as DDT, dieldrin - persistent - biomagnfy Organophosphates:such as malathion and parathion - not persistent and do not biomagnify - but are highly toxic Narrow-spectrum agents: toxic to a more selective group of organisms.
Conventional Chemical Pesticides Advantages:Disadvantages: Save lives (decreased malaria) Kill natural pest enemies Increased food supply Can harm wildlife and people Can promote genetic resistance Expensive to farmers- and cost can increase (pesticide treadmill) The pesticide neonictinoid is suspected to be a primary cause of the bee colony collapse epidemic.
Pesticide Treadmill Because: a pesticide may kill beneficial insects that would decrease pest population Pests may develop resistance to pesticide Farmers often need to add increasing amounts of pesticide for it be effective.
Pesticide Regulations Federal Insecticide and Fungicide Regulation Act (FIFRA), 1972 Overseen by EPA, USDA and FDA. EPA to assess new pesticides, but inadequate funds Food Quality Protection Act, 1996 Reduce levels of pesticide residues if inadequate information on pesticide’s safety.
Pheromone Traps: Sticky traps with pheromones (chemical messages released by organism for mating signals or other communication) can be used to lure pests. Cultural Practices: “Fool the pest” - rotation of crops Biological controls such as beneficial insects -Homes for pest enemies Hormones to disrupt pest life cycle Alternatives to Pesticides
Integrated Pest Management: - Combination of cultural, biological and chemical tools - Monitoring of pests at economically tolerable level -Doesn’t use broad spectrum pesticides Brazil reduced pesticide usage by 90% using IPM