IAS 2011 — Environment & Ecology Environment & Ecology

2011mcqmedium

The Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon ?

Official previous-year question

Verified 2 Aug 2026.

Options

AIt has a high rainfall that supports luxuriant vegetative growth
BIt is a confluence of different bio-geographical zones
CExotic and invasive species have not been introduced in this region
DIt has less human interference

Did you get this right?

Solution

Correct Option (B)

The Himalayan range exhibits high species diversity primarily because it serves as a significant biogeographical confluence. It is situated at the intersection of various major biogeographical realms, such as the Palearctic, Indo-Malayan, and Oriental regions. This convergence facilitates the mixing of species from different climatic zones, including temperate, tropical, alpine, and subtropical environments. Consequently, it supports an exceptional variety of flora and fauna, leading to high species richness and endemism across its diverse altitudinal gradients and microclimates.

Incorrect Options

Option 1: While high rainfall generally supports luxuriant vegetative growth, it is not the most appropriate or fundamental reason for the extraordinary species diversity in the Himalayas. The primary driver is the unique ecological convergence of different biogeographical zones, rather than precipitation alone.
Option 3: The absence of exotic and invasive species is not a defining characteristic or the primary reason for the high species diversity in the Himalayas. Many regions, including parts of the Himalayas, can be susceptible to the introduction of such species, and their presence or absence does not explain the inherent richness of the native biodiversity.
Option 4: Although certain remote parts of the Himalayas experience less human interference, many areas are subject to significant human activities, including settlement, agriculture, tourism, and resource extraction. Therefore, "less human interference" is not a universally applicable or the most appropriate reason for the overall high species diversity of the entire range.

Your note

IAS Environment & Ecology in other years

Environment & Ecology 2026 Environment & Ecology 2025 Environment & Ecology 2024 Environment & Ecology 2023 Environment & Ecology 2022 Environment & Ecology 2021 Environment & Ecology 2020 Environment & Ecology 2019 Environment & Ecology 2018 Environment & Ecology 2017 Environment & Ecology 2016 Environment & Ecology 2015

More IAS Environment & Ecology questions

Consider the following statements about Rhynchostylis retusa (Foxtail orchid): 1. It is an epiphytic orchid. 2. The species is endemic to North-east India. 3. It is the State flower of Arunachal Pradesh and Assam. Which of the statements given above is/are correct?

2026medium

Which of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience? 1. Mangroves reduce tidal energy and store freshwater, making them ideal sites for paddy cultivation in saline estuarine belts. 2. Their salt-sensitive roots filter seawater, making mangroves key to converting coastal land into freshwater aquaculture zones. 3. By withstanding tidal surges and offering biomass resources, mangroves function both as natural bio-shields and livelihood bases for rural communities. Select the answer using the code given below :

2026medium

Which of the following statements with regard to the arrival of Amur Falcons at Doyang Lake in Nagaland each year from Mongolia is/are correct? 1. It showcases how sustained local conservation efforts can contribute to the arrival and protection of international migratory birds. 2. It reflects the global success of advanced tracking technologies that guide migratory birds back to their stopover sites. 3. It confirms that Amur Falcons have adapted to permanent residency in India due to favourable habitat changes. Select the answer using the code given below :

2026medium

Which one of the following is the first Plan Vivo certified Reducing Emissions from Deforestation and Forest Degradation (REDD+) project in India?

2026medium

With respect to the Western Hoolock Gibbons, which of the following statements is/are correct? 1. A Sanctuary in North-east India is home to this ape species listed as Endangered in the International Union for Conservation of Nature (IUCN) Red List. 2. They have specialized brachiation and can easily swing between trees. 3. They possess a strong and heavy build like gorillas, yet are remarkably agile tree climbers. Select the answer using the code given below :

2026medium

View all Environment & Ecology questions

Keep practicing Environment & Ecology

Work through every IAS Environment & Ecology PYQ, year by year.

Browse all Environment & Ecology topics

Correct Option (B)

Incorrect Options

Option 1: While high rainfall generally supports luxuriant vegetative growth, it is not the most appropriate or fundamental reason for the extraordinary species diversity in the Himalayas. The primary driver is the unique ecological convergence of different biogeographical zones, rather than precipitation alone.
Option 3: The absence of exotic and invasive species is not a defining characteristic or the primary reason for the high species diversity in the Himalayas. Many regions, including parts of the Himalayas, can be susceptible to the introduction of such species, and their presence or absence does not explain the inherent richness of the native biodiversity.
Option 4: Although certain remote parts of the Himalayas experience less human interference, many areas are subject to significant human activities, including settlement, agriculture, tourism, and resource extraction. Therefore, "less human interference" is not a universally applicable or the most appropriate reason for the overall high species diversity of the entire range.