As scientists have developed more productive crop varieties, farmers have switched from growing many traditional varieties to new high-yield varieties. for example, in peru, the indians once grew 500 native varieties of potatoes. that number has been reduced to about twenty major potato varieties, worldwide. why is it potentially dangerous to reduce the number of crop species in potatoes? a) it reduces the variety of crops available for human diets. b) it requires a larger investment than small farmers can make. c) it makes the overall crop more susceptible to pests or disease. d) it could reduce or cause the extinction of some predatory insects. submit

Option C, It makes the overall crop more susceptible to pests or disease.

Explanation:

An organism keeps on evolving and varying from its previous generation based on the gene pool. The larger is the gene pool, the higher is the scope of variation.  

Now in this case farmers have stopped a growing traditional crop, which means there are only limited genes in the entire gene pool of hybrid potato which are free to vary based on the mating scenario.  

This limit on variation based on reproduction will ultimately reduce the natural ability of a crop to generate characteristics that could support it to survive in adverse condition. Thus, GMO may become more susceptible to the new evolved species of pest (which is free to evolve naturally)

Hence, option C is correct