4.Christopher Columbus introduced horses, sugar plants, and disease to the new world, while facilitating the introduction of new world commodities like sugar, tobacco, chocolate, and potatoes to the old world.
5.positive-The old world welcomed these new crops because the Columbian exchange greatly increased the food supply with the massive exchange of crops occurring in the old world an increased food supply In turn increased the human reproductive rate more food meant more people survived to the reproductive age thereby increasing the population in the old world.
Negative-The Colombian Exchange also caused many people to die, diseases were sent to the New World from Europe and with all of the conquering of the new world, people were treated very cruel by the Europeans.
