ENVS 2040 Lecture Notes - Lecture 10: Irrigation, Protonema, Sporangium
Document Summary
Lecture 12 (ii): crown gall and gmo crops. 1916: erwin f. smith wrote a report about crown gall that likened it to human cancer. Prior to 1980s genetic modification of crops required introduction of new genes through breeding: however, after 1980 , 1983: gene-splicing, bean protein expressed in sunflower plant, 1985: first release of genetically-engineered organism into the environment (monsanto"s crown- gall resistant tobacco) Scientists discovered that if the tumor- inducing/virulent gene is removed, plasmids can still infect hosts but do not cause the disease. Foreign genes can then be inserted into ti plasmids where that virulent gene was: transferred to dna of another plant. Enables transfer of genes between organisms that normally would not be achieved through breeding. For example: monsanto tried to control technology so farmers couldn"t grow seeds the following year suicide gene so no viable progeny and farmers couldn"t produce their own seed.