Tham Shi YuanWong Qin Jiang

Video:◦ GM Food and You

Selective Breeding Genetic Engineering

Test many plants for a certain trait

Cross-breed that plant with the crop

Repeat until a strain of crop with that trait is found

Conclusion: Unspecific so no confirm amount of time needed

Find and isolate gene that results in a certain trait◦ Can be from non-plant

organisms Insert gene into crop

Conclusion: Specific so much faster to do

BenefitsControversies

Tolerance / Resistant to:◦ Pests (less pesticides used)◦ Herbicides◦ Diseases◦ Cold◦ Drought◦ Salinity

Increases survival of crops Higher crop yield

More crops can be grown in less arable land

https://www.achooallergy.com/blog/images/gm_strawberries.jpg

Increased nutritional value◦ Undernourishment is a major problem in third

world countries such as those in Africa

Food can stay fresh for longer

Food may taste better

Health risks Possible unknown, undetermined effects

◦ Some long term consequences cannot be well predicted

◦ Difficult to predict biological properties from the knowledge of its chemistry

Allergenicity◦ Combining genes may cause possible new

allergens

Environmental hazards Unintended harm to other species

◦ Designed to kill crop-eating pests but may harm “innocent” creatures

Gene transfer to other plants◦ Due to cross-breeding of plants◦ Can be prevented by planting GM crops further

away or make the crop unable to produce pollen

Religious issues Using genes of sacred animals

◦ Break religious dietary laws◦ Judaism and Islam are concerned with using

genes of pigs

Economical concerns Copyright

◦ Patent enforcing difficult as cross-breeding may spread the gene Solution: Make seeds produced by crop sterile Problem: Huge financial burden on third world

farmers◦ Patenting may increase cost, making it

unaffordable for poor farmers

Bt Crops in IndiaGM Rice in China

Bt Cotton, Bt Brinjal, Bt Corn◦ Produced by inserting a gene from the soil

bacterium Bacillus thuringiensis into the crop◦ Induces the plant to produce its own Bt toxin◦ Bt toxin disrupts digestive processes and thus

kills the insects However,

◦ Bt crops as part of GE technology cannot directly increase yields

◦ Secondary pests are immune to Bt toxin

biotechnews.gov.in/new_img/full3be.jpg

Health risks Problems with growth, organ development

and damage, immune responsiveness, etc. Adverse human health impacts in farm Factory workers with allergies Itching skin, eruptions on body, swollen

faces, etc. Powerful immune responses and abnormal

cell growth in mice

Environmental hazards Increased pest resistivity

◦ Insects are exposed to Bt toxin regularly◦ Develop a stronger and quicker resistance to

the toxin◦ Bt sprays become less effective◦ Effective life of Bt crop not more than 2-3 years◦ Evidence: After 12 to 13 generations, toxin was

ineffective when used on bollworm

Gene flow to wild relatives◦ Bt crops grown close to wild relatives◦ Bt gene can be spread through pollen transfer◦ Wild plants act as weeds◦ Contaminates other species

Unable to address complexity of pest attack◦ Use of pesticides is still required◦ Secondary pests which are immune to Bt toxin

become primary pests

Overview of study:◦ GM rice grown in field trials◦ Benefited local farmers

Higher crop yield Reduced pesticide use Fewer pesticide-related health problems

◦ Shows whether GM food crops can actually improve farmer welfare

http://www.treehugger.com/gm-rice-h-i-001.jpg

Economic concerns High total input cost, no increase in yield

◦ Costs of seeds of Bt crops are higher◦ Pesticides have to be used to get rid of

secondary pests

http://www.topnews.in/health/files/Pesticide.jpg

Potential benefits Higher crop yields

◦ Yields of GM rice was 9 times greater than conventional rice

Reduced use of pesticides◦ GM rice: pesticides applied less than once per season◦ Conventional rice: pesticides applied 3.7 times per

season◦ Quantity of pesticides applied to conventional rice

was 8-10 times as high as that applied to GM rice◦ Contributes to improved health of farmers

GM foods can solve world hunger and undernourishment problems

Possibly help to save the environment through lower use of chemicals

However, we must proceed with caution as this has the potential to cause disastrous consequences for messing with nature

http://www.masternewmedia.org/images/modded.jpg http://www.csa.com/discoveryguides/gmfood/

overview.php http://www.howstuffworks.com/question148.htm http://en.wikipedia.org/wiki/

Genetically_modified_food_controversies http://www.greenpeace.org/india/campaigns/say-no-

to-genetic-engineering/ge-crops-in-india-the-story http://www.csa-india.org/downloads/GE/

bt_brinjal_briefing_paper.pdf http://www.jyi.org/news/nb.php?id=208

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