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Environment & Ecology question from JKAS Prelims, 2021 by JKPSC

The non-native species successfully establishes in the introduced environment and causes the damage to the environment due to

 1) Better adaptation to the new environment 
2) All the niches are utilized by the native species
3) Absence of natural enemies in the introduced region 
4) Low biotic potential

Choose the correct option.

Last updated Jun 24, 2026
Correct Answer: Option B — 1 and 3
Non-native (or invasive) species disrupt ecosystems because they often possess specific advantages that allow them to outcompete local flora and fauna:

Statement 1 (Better adaptation): Invasive species are typically generalists with high phenotypic plasticity, meaning they can thrive in a wide range of environmental conditions and utilize diverse food sources better than specialized native species.

Statement 3 (Absence of natural enemies): This is often the most significant factor. In their home range, these species are kept in check by specific predators, parasites, or diseases. In a new environment, those "natural checks" are missing, allowing their population to grow unchecked.

Why the others are incorrect:

Statement 2: If all niches were already fully utilized by native species, the non-native species would struggle to find space or resources to establish itself.

Statement 4: Successful invasive species usually have high biotic potential (the ability to reproduce rapidly and in large numbers), not low.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.

About this question

JKPSC JKAS 2021 Prelims

Details

Exam JKPSC
Recruitment JKAS
Stage Prelims
Year 2021
Subject Environment & Ecology
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