Commensalism: One Species Benefits — NEET Biology
✅ Asked in NEET 2024Assertion (A): The interaction in which one species benefits and the other is neither harmed nor benefitted is known as commensalism. Reason (R): Egrets always forage close to where the cattle are grazing, otherwise, it is difficult for the egrets to find the insects and catch them.
Assertion (A): The interaction in which one species benefits and the other is neither harmed nor benefitted is known as commensalism. Reason (R): Egrets always forage close to where the cattle are grazing, otherwise, it is difficult for the egrets to find the insects and catch them.
Which of the following is not an example of mutualism?
Answer & NCERT explanation
Correct answer: B — Both (A) and (R) are True, but (R) is not the correct explanation of (A)
Both statements are true. Assertion correctly defines commensalism as interaction where one species benefits while other is neither harmed nor benefitted. Reason correctly explains that egrets forage near cattle to easily catch insects disturbed by cattle movement. However, Reason doesn't explain WHY this interaction is called commensalism - it just describes the mechanism. The explanation for commensalism would focus on benefits to egret and neutral effect on cattle.
Read more NCERT concept on the PYQ
Commensalism: This is the interaction in which one species benefits and the other is neither harmed nor benefited. An orchid growing as an epiphyte on a mango branch, and barnacles growing on the back of a whale benefit while neither the mango tree nor the whale derives any apparent benefit. The cattle egret and grazing cattle in close association, a sight you are most likely to catch if you live in farmed rural areas, is a classic example of commensalism. The egrets always forage close to where the cattle are grazing because the cattle, as they move, stir up and flush out insects from the vegetation that otherwise might be difficult for the egrets to find and catch. Another example of commensalism is the interaction between sea anemone that has stinging tentacles and the clown fish that lives among them. The fish gets protection from predators which stay away from the stinging tentacles. The anemone does not appear to derive any benefit by hosting the clown fish.
Commensalism is a symbiotic relationship where one species benefits while the other is neither harmed nor benefited. NTA specifically tests the cattle egret example: egrets forage near grazing cattle to catch insects stirred up by them, while cattle gain nothing. Students often confuse commensalism with mutualism (both benefit) or parasitism (one harmed). The key distinction: the cattle egret benefits, but cattle experience no harm or benefit—it's not mutual gain. Remember: commensal = one-sided benefit with no cost to the host organism. This concept appears repeatedly because it tests understanding of symbiotic relationship categories, critical for ecology sections.
What does NCERT say about Commensalism This interaction which?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.