Amazon Rainforest: The Greatest Biodiversity on Earth
Biology · Biodiversity and Conservation · NEET
The Amazon rainforest in South America has the greatest biodiversity on Earth. NCERT says it is home to more than 40,000 species of plants, 1,25,000 invertebrates, 3,000 fishes, 1,300 birds, 427 mammals, 427 amphibians and 378 reptiles. Memory hook: it lies near the equator (tropics), so by the latitudinal gradient it is the richest place on the planet.
Relative number of species in the Amazon rainforest per NCERT: invertebrates dominate, followed by plants, fishes, birds and mammals. This order is a frequent NEET question.
Your doubts, answered
Which region on Earth has the highest species diversity?
The Amazon rainforest (largely tropical, in South America) has the greatest biodiversity on Earth. In NEET options it beats Himalayas, Western Ghats and Madagascar because those are rich hotspots but do not have more total species than the Amazon.
How many species does the Amazon rainforest have (NCERT numbers)?
NCERT lists: more than 40,000 species of plants, 1,25,000 invertebrates, 3,000 fishes, 1,300 birds, 427 mammals, 427 amphibians and 378 reptiles. Learn these exact numbers because NEET asks direct value and order questions.
What is the descending order of species in the Amazon rainforest?
Invertebrates (1,25,000) > Plants (40,000) > Fishes (3,000) > Birds (1,300) > Mammals (427). Invertebrates are always the largest group, so this order follows the general rule that animals (mostly invertebrates) outnumber plants.
Why does the Amazon have the highest biodiversity?
It sits near the equator (tropical latitude). By the latitudinal gradient, diversity is highest in the tropics and falls towards the poles. Reasons include a long, undisturbed evolutionary time, a constant warm climate, and high solar energy and productivity.
Is the Amazon a biodiversity hotspot?
NCERT names the Amazon as the place with the greatest biodiversity on Earth, but the 34 biodiversity hotspots (Norman Myers) are a separate list based on high endemism plus threat. Do not confuse 'greatest biodiversity' (Amazon) with 'biodiversity hotspot' (like Western Ghats).
⚠️ The NEET trap ✗ Western Ghats or Himalayas have the highest species diversity because they are Indian biodiversity hotspots. ✓ The Amazon rainforest has the greatest biodiversity on Earth. Western Ghats and Himalaya are hotspots (high endemism + threat), but the Amazon has more total species. 🧠 Hotspot is not the same as most-diverse. NEET mixes these two facts in the same option list to trap you.
Real NEET questions
NEET 2020
Which of the following regions of the globe exhibits highest species diversity?
A · Himalayas
B · Amazon forests ✓
C · Western Ghats of India
D · Madagascar
Solution: NCERT (Ch 13) states the largely tropical Amazonian rain forest in South America has the greatest biodiversity on Earth. Himalayas, Western Ghats and Madagascar are biodiversity-rich but do not exceed the Amazon in total species.
reNEET 2026
Arrange the following in descending order of the number of species in the Amazonian rain forest: (a) plants, (b) birds, (c) fishes, (d) invertebrates, (e) mammals.
A · (d) > (a) > (c) > (b) > (e) ✓
B · (a) > (d) > (c) > (b) > (e)
C · (e) > (b) > (a) > (c) > (d)
D · (a) > (c) > (b) > (e) > (d)
Solution: NCERT counts for the Amazon: invertebrates ~1,25,000 > plants ~40,000 > fishes ~3,000 > birds ~1,300 > mammals ~427. So the order is (d) invertebrates > (a) plants > (c) fishes > (b) birds > (e) mammals.
Solved Biodiversity and Conservation NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
How many plant species are in the Amazon rainforest?
More than 40,000 species of plants, as per NCERT Class XII Biology, Chapter 13.
Does the Amazon have more animals or plants?
More animals. Invertebrates alone number about 1,25,000, far more than the 40,000 plant species, which matches the general rule that animal species outnumber plants.
Is the Amazon rainforest in India?
No. It is in South America (mainly Brazil). India's rich areas are the Western Ghats, Himalaya, Indo-Burma and Sundaland hotspots.
Why is the Amazon called the greatest biodiversity on Earth?
Because it holds the largest number of species of any region, driven by its tropical location, long evolutionary time, constant climate and high productivity.
