The greatest biodiversity on the earth is seen in :

The correct answer is Option (2) → The Amazon rain forest

Option (1) Taiga forest — Incorrect. The coniferous taiga lies at high latitudes, where species diversity is low.

Option (2) The Amazon rain forest — Correct. The largely tropical Amazonian rain forest in South America has the greatest biodiversity on earth. It is home to more than 40,000 species of plants, 3,000 of fishes, 1,300 of birds and so on.

Option (3) Tundra forest — Incorrect. The tundra is a cold, treeless region with few species.

Option (4) Deserts — Incorrect. Deserts are dry and support far fewer species. NCERT says species diversity is greatest in the tropics, and names the tropical Amazonian rain forest as the richest of all.

NCERT Extract:
Patterns of Biodiversity – “… The largely tropical Amazonian rain forest in South America has the greatest biodiversity on earth-it is home to more than 40,000 species of plants, 3,000 of fishes, 1,300 of birds, 427 of mammals, 427 of amphibians, 378 of reptiles and of more than 1,25,000 invertebrates.”