Q. Which one of the following groups of plants was domesticated in the New World and introduced into the Old World? (UPSC Prelims 2019)
Answer: Tobacco, cocoa and rubber
Notes: The correct answer is [A] Tobacco, cocoa and rubber. The "New World" refers to the Americas, while the "Old World" refers to Europe, Africa, and Asia. The transfer of plants, animals, and diseases between these hemispheres following Christopher Columbus's voyages is known as the Columbian Exchange.

• Tobacco, Cocoa, and Rubber (Statement A – Correct): All three originated in the Americas. Tobacco was used by Native Americans for medicinal and ritual purposes. Cocoa (Cacao) is native to the Amazon basin and was central to Mayan and Aztec cultures. Rubber is derived from the Hevea brasiliensis tree, indigenous to the Amazon rainforest.
• Cotton (Statements B & C): While some species of cotton are native to the New World (like Gossypium hirsutum), other varieties were already known and used in the Old World (India and Egypt) for millennia. Therefore, it is not uniquely a New World introduction.
• Coffee (Statements C & D – Incorrect): Coffee is native to the highlands of Ethiopia (Old World) and was introduced to the Americas later by European colonizers.
• Sugarcane (Statement C – Incorrect): Sugarcane originated in Southeast Asia and New Guinea (Old World) and was brought to the New World by the Spanish and Portuguese for plantation farming.
• Wheat (Statement D – Incorrect): Wheat was one of the first crops domesticated in the Fertile Crescent of the Middle East (Old World).

Other notable New World crops introduced to the Old World include potatoes, maize (corn), tomatoes, and chili peppers, which fundamentally changed global diets and demographics.