Who brought new domestic animals food plants and diseases to the Western Hemisphere?

The answer is Europeans, specifically Christopher Columbus and the subsequent waves of European explorers, colonists, and settlers.

Here's why:

* Columbian Exchange: The period of transatlantic exchange of plants, animals, diseases, and ideas between the Old World (Europe, Asia, Africa) and the New World (North and South America) is known as the Columbian Exchange.

* Introduction of New Species: Columbus's voyages and the colonization that followed brought a vast array of new species to the Western Hemisphere, including:

* Domestic Animals: Horses, cattle, pigs, sheep, goats, chickens, and others.

* Food Plants: Wheat, barley, rice, sugar cane, coffee, oranges, and many more.

* Diseases: Measles, smallpox, influenza, typhus, and others.

It's important to note that this exchange wasn't a one-way street. The New World also provided the Old World with new food plants like potatoes, tomatoes, corn, and beans. However, the introduction of diseases from Europe had devastating effects on the indigenous populations of the Americas.