Question

Which one of the following pair does NOT show commensalism?

• A. Sea-anemones – crab
• B. Shark – Remora fish
• C. Barnacles – whale
• D. Cow – bacteria

Hint:

Commensalism = one benefits, other unaffected;\; Mutualism = both benefit.

Answer 1

The Correct Option is D

Step 1: Understanding commensalism.
Commensalism is an interaction where one organism benefits while the other is neither harmed nor benefited.
Step 2: Evaluating the given pairs.
Sea-anemone and crab, shark and remora, and barnacles and whale are classic examples of commensalism.
In cow–bacteria interaction, both organisms benefit: bacteria get shelter and nutrients, while the cow benefits from cellulose digestion.
Step 3: Analysis of options.
(A) Commensalism.
(B) Commensalism.
(C) Commensalism.
(D) Mutualism, not commensalism.
Step 4: Conclusion.
The pair that does not show commensalism is cow – bacteria.