Question

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, there are about 500 native varieties of potatoes that Indians once grew. This has been reduced to about 20 genetically improved potato varieties worldwide .Besides the number of varieties of potatoes being reduced, what else is reduced by this practice? A) the potato gene pool B) human dietary choices C) types of soil nutrients D) food chains that include potatoes

Answer 1

The answer is A. The reduction in variety reduces the number of alleles for each gene in the gene pool.   This reduces the variations in the phenotypes of the crops.  A disadvantage of this phenomenon is that it would be difficult for the crops to withstand environmental changes and calamities because there is no wide variation on which natural selection could act upon to enable the crops to adapt to these changes.

Answer 2

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