UNIT ____:  Genetic Modification                           Name:  _____________________

Essential Idea(s):

Biologists have developed techniques for artificial manipulation of DNA, cells and organisms

3.5.U4:  Genetic modification is carried out by gene transfer between species.

• Outline how the universality of the genetic code allows for gene transfer between species.

3.5.A2:  Gene transfer in bacteria using plasmids makes use of restriction endonucleases and DNA ligases.

• Describe a technique for genetic modification including plasmids, restriction enzymes, reverse transcriptase and ligase.
• Outline why plasmids with genes coding for antibiotic resistance are chosen as vectors in gene transfer between species.

2.7.A2:  Production of human insulin in bacteria as an example of the universality of the genetic code allowing gene transfer between species.

• Outline the source and use of pharmaceutical insulin prior to the use of gene transfer technology.
• Outline the benefits of using gene transfer technology in the production of pharmaceutical insulin.

3.5.NOS:  Assessing risks associated with scientific research- scientists attempt to assess the risks associated with genetically modified crops or livestock.

• State two ways in which the risk of scientific research can be assessed.

3.5.A3:  Assessment of potential risks and benefits associated with genetic modification of crops.

• Outline potential environmental, health and agricultural benefits and risks associated with genetic modification of crops.
• Assess the risks and benefits of an example of a genetically modified crop (i.e. golden rice).

3.5.S3:  Analysis of data on risks to monarch butterflies of Bt crops.

• Outline the formation and use of Bt crops in agriculture.
• Assess the impact of Bt corn on monarch butterflies.

Genetic Modification – overview                                                

1. Genetic modification is carried out by gene transfer between species.  

Restate in your own words:

         What does UNIVERSAL mean in this context?

2. Genetic modification is possible because the genetic code is universal – so when genes are transferred between species the amino acid sequence translated from them is unchanged.

3. There are many ways in which genetic modification can occur.  We will focus on ___________________ ________.  

What does GMO stand for?

What does FOREIGN mean in this context?

1. In this process, a foreign gene is added which will enable the GMO to carry out a new genetic program.

2. Organisms altered in this way are referred to as __________________.

Gene Transfer in Bacteria using Plasmids 

Genetic Modification – examples

Analyzing Risks to Monarch Butterflies of Bt crops.

1. Background:

2. Laboratory bioassays of pollen fed to first instar monarchs for 4 days on leaf discs or whole detached leaves of common milkweed, A. syriaca, indicate that pollen from Bt corn causes mortality and sublethal effects, such as growth inhibition, at very low concentrations. Mortality was evident, even at low densities of pollen, but was variable (Impact of Bt corn pollen on monarch butterfly populations: A risk assessment, PNAS October 9, 2001 https://www.pnas.org/content/98/21/11937)

       Implication:

3. Field studies compared the mortality of monarch larvae when placed near fields with Bt corn and those without.  (Impact of Bt corn pollen on monarch butterfly populations: A risk assessment, PNAS October 9, 2001 https://www.pnas.org/content/98/21/11937)

Implication:

4. Milkweed is becoming rare as more land is converted to crop land and as more corn engineered to be herbicide resistant is planted.  (Unravelling the annual cycle in a migratory animal: breeding-season habitat loss drives population declines of monarch butterflies, Journal of Animal Ecology 2014, http://norrislab.ca/wp-content/uploads/Flockhart-et-al.-In-press.pdf)

NOTE:  HERBICIDE resistance corn is not the same thing as Bt corn.  Bt corn is an INSECTICIDE not an HERBICIDE.

Implication:

5. Historical analysis of monarch trends indicate that Monarch butterfly and milkweed declines substantially predate the use of genetically modified crops (PNAS February 19, 2019, https://www.pnas.org/content/116/8/3006)

Implication:

Genetic Modification – Benefits and Risks

Genetic Modification – assessing the risks