Use the following chart summarizing the columbian exchange to answer the question:
europe and africa to americas
americas and europe to africa
plants
collee, sugar cane, bananas, melons, olives,
barley, wheat, oats, rice, ragweed, bluegrass,
dandelions, daisies, clover
maize (corn), potatoes, sweet potatoes, peanuts, squash,
pumpkins, tomatoes, peppers, papaya, guava, avocado,
pineapple, manioc, cacao, chicle, tobacco
animals
llamas, alpacas, turkeys, guinea pigs
humans
few
cattle, chickens, horses, goats, sheep, pigs
african slaves, european merchants, officials,
priests, and settlers
smallpox, yellow fever, malaria, measles,
chicken pox, influenza, common cold
diseases
syphilis
in which category on the chart was the exchange most harmful to the new world?
the introduction of rare species of plants that natives refused to use
the introduction of animals that reduced the need for indigenous labor
the introduction of new forms of classes for ordering the known world
the introduction of diseases that were not known in the new world