Q.22

Match the pair of orgamisms in Group I with their community interaction pattern in

Group II.

(A) P-3, Q-1, R-4, S-2

(B) P-3, Q-4, R-1, S-2

(C) P-4, Q-1, R-3, S-2

(D) P-2, Q-3, R-1, S-4

The correct answer is option (A): P-3, Q-1, R-4, S-2.

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Correct matching of interactions

• P. Cattle egrets – African buffalo → 3. Commensalism
  Cattle egrets feed on insects flushed out by the movement of large mammals such as African buffalo, gaining food while the buffalo is typically neither harmed nor significantly benefited, which defines commensalism (+/0 interaction).

• Q. Lynx – Fox → 1. Competition
  Lynx and fox are carnivorous mesopredators that can overlap in prey use and space, leading to interspecific competition for shared resources, even though foxes may also scavenge on lynx kills.

• R. Acacia tree – Pugnacious ants → 4. Mutualism
  Classic ant–acacia systems are mutualistic: the acacia provides food (nectar, Beltian bodies) and shelter in thorns, while aggressive ants defend the plant from herbivores and competing vegetation, benefiting both partners (+/+ interaction).

• S. Leopard – Antelope → 2. Predation
  Leopards are carnivores that hunt ungulates such as antelopes as their primary prey, which is a textbook example of predation (+/− interaction where predator benefits and prey is harmed).

This pattern yields P-3, Q-1, R-4, S-2, so option (A) is correct.

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Why the other options are incorrect

Option (B): P-3, Q-4, R-1, S-2

• Q-4 would mean lynx–fox = mutualism, but there is no evidence that both species benefit; instead they mostly compete for similar prey and may engage in intraguild predation, fitting competition rather than mutualism.

• R-1 would mean acacia–ants = competition, which is wrong because the well‑studied ant–acacia association is beneficial to both, not a competitive interaction.

Option (C): P-4, Q-1, R-3, S-2

• P-4 treats cattle egret–buffalo as mutualism, which would require a clear benefit to the buffalo; most ecological sources classify this interaction as commensalism, since the buffalo is largely unaffected.

• R-3 labels acacia–ants as commensalism, ignoring the plant’s gain in protection from herbivores; the reciprocal benefit makes it mutualism, not commensalism.

Option (D): P-2, Q-3, R-1, S-4

• P-2 claims cattle egret–buffalo = predation, but the egret preys on insects, not on the buffalo itself; the direct interaction between egret and buffalo is commensal.

• Q-3 would mean lynx–fox = commensalism, but they share prey and may kill each other’s young; such negative effects make the relationship competitive rather than neutral.

• R-1 again misclassifies the ant–acacia mutualism as competition, which contradicts experimental evidence of protection and growth benefits to the plant.

• S-4 would mean leopard–antelope = mutualism, whereas the antelope is killed and consumed; this is a clear predator–prey interaction.

Using the key phrase community interaction patterns cattle egret buffalo lynx fox acacia ants leopard antelope, this explanation clarifies why option (A) alone matches each pair with its correct ecological interaction.