AP® Biology

Free Version

Upgrade subject to access all content


Irish Potato Famine


In the 1700s, over two hundred different varieties of potatoes were being grown in Ireland, each variety with its own unique size, shape, flavor, color, growth pattern, and ability to resist disease.

By the early 1800s, there were less than five different varieties of potatoes being grown in Ireland, the main variety being called the "Irish Lumper." In 1845, the Phytophthora infestans disease was introduced to the country and over two-thirds of the country's potato crops were destroyed.

Which of the following would be the most cost-effective way for potato farmers in Ireland today to avoid future disease-caused crop losses?


They should use artificial selection to breed resistance to Phytophthora infestans by periodically exposing their crops to the disease and then only using seeds from plants that are least affected.


They should genetically engineer their potato crops with a gene that allows the plants to produce their own pesticide chemicals.


They should only grow potatoes every other year so that Phytophthora infestans is not given an environment that favors spreading.


They should grow multiple varieties of potatoes in their fields, so that if Phytophthora infestans is re-introduced, some varieties of potato might possess genetic traits that confer natural resistance to the organism.