Ecology, Ecosystem and Functions of Ecosystem: UPSC Previous Year Questions (Environment and Ecology)
1 previous year UPSC Prelims question on Ecology, Ecosystem and Functions of Ecosystem (Environment and Ecology). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
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UPSC 2000Environment and Ecology · Ecology, Ecosystem and Functions of Ecosystem
Q1. Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called:
Explanation
Keystone species play a crucial role in maintaining eco-system structure and function, having a disproportionate impact relative to their abundance. Like the keystone in an arch, they support the stability of the entire system. These species influence population sizes, modify the environment, and affect species diversity and community composition. Removing a keystone species can disrupt the ecosystem, leading to biodiversity loss and instability. Some of the Keystone Species are: Sea Otters(kelp forest ecosystem). Wolves and other top predators(Grassland ecosystem), Elephants(Savannah), Beavers and Starfish. Options (b), (c) and (d) are incorrect:
Allopatric species are species that evolve separately due to geographic isolation, Eg. African and Indian elephants. Sympatric species are species that evolve separately within the same geographic area. Threatened species are species at risk of becoming endangered in the near future due to factors like habitat loss, climate change, and human activities.
Answer key for these questions
Q
UPSC year
Correct answer
1
2000
(a) Keystone species
Frequently asked questions
How many previous year UPSC questions are there on Ecology, Ecosystem and Functions of Ecosystem?
This page covers 1 previous year UPSC Prelims GS Paper-I questions on Ecology, Ecosystem and Functions of Ecosystem (Environment and Ecology), asked from 1996 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Ecology, Ecosystem and Functions of Ecosystem?
Questions on Ecology, Ecosystem and Functions of Ecosystem (Environment and Ecology) are available for 12 years, from 1996 to 2025. Use the Year filter to practise a single paper.
