Q71.Which of the following statements are true?
A. Dominant species have a large effect on the community because of its abundance.
B. Keystone species have a large role in community, out of proportion to its abundance.
C. Indicator species provide information on the overall health of an ecosystem.
D. Flagship species is the single, large and instantly recognisable species.
Choose the correct answer from the options given below :
(1) A and D Only
(2) A and B Only
(3) A, B and C Only
(4) A, B, C and D
The correct answer is option (4): A, B, C and D.
Statement Verification
All statements accurately define ecological roles: Dominant species (A) impact communities through high biomass/abundance, controlling resources and suppressing subordinates. Keystone species (B) disproportionately shape ecosystems despite low numbers (e.g., sea otters controlling urchins). Indicator species (C) signal environmental health via sensitivity (e.g., lichens for air pollution). Flagship species (D) are charismatic “umbrella” icons like tigers for conservation campaigns.
Option Analysis
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Option (1) A and D Only: Misses keystone (B) and indicator (C) roles, both core ecology concepts.
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Option (2) A and B Only: Excludes indicator species (C) and flagship (D), incomplete coverage.
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Option (3) A, B and C Only: Omits flagship species (D), used in biodiversity policy.
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Option (4) A, B, C and D: All true—comprehensive matching of definitions to roles.
Introduction: Keystone Species Large Role in Community Ecology
NEET ecology tests species roles via statements on dominant, keystone, indicator, and flagship types. All four definitions hold true (option 4), distinguishing impacts from abundance to conservation icons. This guide verifies each, eliminates distractors, and preps exam success.
Species Roles Decoded
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Dominant (A): High biomass controls community structure (e.g., grasses in prairies suppress diversity).
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Keystone (B): Low abundance, high impact—ecosystem engineers like wolves maintain balance.
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Indicator (C): Bioindicators reveal health (lichens = clean air; Tubifex worms = pollution).
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Flagship (D): Charismatic single species (pandas, tigers) drive funding/protection.
Why Option (4): All Statements Correct
No falsehoods—each matches textbook ecology. Trap: Undervaluing flagships as “marketing” vs. ecological validity.
Ecology Species Comparison
NEET Prep: Species Role Mastery
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Mnemonic: “DKeIF: Dominant-Keystone-Indicator-Flagship.”
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Link: Keystone removal → collapse; indicator decline → degradation.
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PYQ pattern: Match definitions to functions.
