Answer:
From Europe to the Americas: wheat (that grew very well on the land there), vines, horses, cattle, pigs, sheep, goats, and chickens
From the Americas to Europe: maize, potatoes, beans, tomatoes, peppers, peanuts, manioc, papayas, guavas, avocados, pineapples, and cacao
In both areas these new foods added the needed calories and protein to make a healthy diet. With a healthier diet people were able to live longer and this cause the population to grow.