Answe
Step-by-step explanation:
The answer is reduced effectiveness of pesticides.
Genetic engineering has a great advantage in vaccines production or in a pharmaceutical production of desired proteins, such as insulin, human growth hormone, etc. In plant genetic engineering increased drought and salinity tolerance will help plants survive in difficult conditions.
On the other hand reduced effectiveness of pesticides is a disadvantage of using genetic engineering. Genetically modified plants may develop resistance to pesticides, so pesticides are not effective as expected.