Refs

Question 1

Ref about SSNs

Answer 1

Voytas, 2013
- SSNs (single stranded nucleases) e.g. ZFNs, TALENs
- Early paper when CRISPR/Cas9 was just emerging
- SSNs cause double stranded breaks at specific genomic locations
- dsDNA breaks are repaired by NHEJ and HDR, allowing for targeted mutations, gene insertions or deletions
- Potential for off-target effects and unintended mutations

Question 2

Ref about meta-analysis of impacts of genetically modified crops

Answer 2

Klumper & Quaim, 2013
- Meta analysis of 147 original studies, focusing on GM soy, maize and cotton
- 22% increase in yield
- 37% decrease in pesticides
- 68% increase in profit
- Insect resistant crops had higher yield than herbicide tolerant crops
- Developing countries benefited more than developed
- Hopes that findings increase public opinion on GM technology

Question 3

Ref about GM cotton in India

Answer 3

Quaim & Kouser, 2013
- Comprehensive panel data collected over several years from farm households in India where GM insect-resistant cotton was adopted
- Calorie consumption and dietary quality increased among farming houeholds
- 15-20% reduction in food insecurity among cotton producing households
- GM crops positively influenced economic and social situation of farmers

Question 4

Ref about engineering nitrogen fixation in plants

Answer 4

Oldroyd & Dixon, 2014
- Excessive use of inorganic fertilisers in developed countries
- Limited access to fertilisers in developing countries
- Possibility of engineering nitrogen-fixing bacteria into cerals to establish symbiotic relationships similar to those in legumes
- Or incorporation of nitrogenase enzymes into the plant genome, allowing plant to fix nitrogen independently
- However, talks of nitrogenase’s sensitivity to oxygen, posing a challenge for its stable expression and function within plant cells