Around 3 million GM male mosquitoes were released in the Cayman Islands. Suggest why releasing such large numbers of male mosquitoes did not immediately raise the risk of dengue fever transmission.
In Malaysia, both GM male and non-GM male mosquitoes were released so that their dispersal and life span in the wild could be compared. The GM mosquitoes could be recognised because they also carried a gene for green fluorescent protein (GFP). Explain why, in many examples of gene technology, fluorescent markers are preferred to antibiotic resistance genes.
Suggest why this process is called positive feedback.
Explain why, in gene technology, a promoter must be transferred together with the desired gene.
Switching on the gene coding for tTA in the mosquito larvae, rather than in the eggs, makes this method of controlling mosquito numbers more effective. Suggest why this is so.
With reference to Fig. 2.1, suggest how A could prevent death of the GM mosquitoes.
Suggest how large numbers of adult GM male mosquitoes can be produced for release into the wild, starting from an original stock of GM males.
Suggest why there is little risk that the gene carried by these GM mosquitoes will be passed to other organisms from GM mosquitoes that escape or are released into the wild.