The greatest biodiversity on the earth is seen in :

The Amazon rain forest

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

The Amazonian rainforest in South America is known for having the greatest biodiversity on Earth. It is one of the most biodiverse regions on the planet, teeming with an incredible variety of plant and animal species. The Amazon rainforest spans multiple countries, including Brazil, Peru, Colombia, and several others, and it covers a vast area of approximately 6.7 million square kilometers (2.7 million square miles).

The rainforest's exceptional biodiversity is due to its complex and diverse ecosystems, which include tropical rainforests, flooded forests, savannas, and rivers. Within this vast expanse, there are an estimated 40,000 species of plants, 3,000 species of fishes, 1,300 species of birds, 427 species of mammals, 427 species of amphibians, 378 species of reptiles, and more than 125,000 species of invertebrates. It is believed that there might be at least two million insect species waiting to be discovered and named in this region.

The combination of abundant solar energy, high rainfall, and relatively stable temperatures throughout the year provides favorable conditions for a wide array of life forms to thrive in the Amazon rainforest. However, this exceptional biodiversity is also under threat due to deforestation, habitat destruction, and other human activities that pose significant challenges to the conservation of this unique and vital ecosystem.