In commensalism, which statement is true?

In commensalism, which statement is true?

• A. Both species benefit equally.
• B. One species benefits while the other is unaffected.
• C. The host benefits while the symbiont is harmed.
• D. Neither species benefits.

Answer: (B)

In commensalism, one species benefits while the other is unaffected. The benefiting partner gains something like transport, shelter, or access to resources, while the other experiences no real advantage or harm. For example, remoras hitching rides on sharks gain food scraps and a boost in mobility, but the shark is not helped or harmed in any meaningful way. Similarly, barnacles on whales benefit from a moving water current bringing food, while the whale isn’t significantly affected. So the true statement is that one species benefits while the other is unaffected. If both species benefited, that would be mutualism. If the host benefited while the symbiont was harmed, that would be a parasitic or antagonistic relationship. And if neither benefits, that describes a neutral or no interaction.

In commensalism, one species benefits while the other is unaffected. The benefiting partner gains something like transport, shelter, or access to resources, while the other experiences no real advantage or harm. For example, remoras hitching rides on sharks gain food scraps and a boost in mobility, but the shark is not helped or harmed in any meaningful way. Similarly, barnacles on whales benefit from a moving water current bringing food, while the whale isn’t significantly affected.

So the true statement is that one species benefits while the other is unaffected. If both species benefited, that would be mutualism. If the host benefited while the symbiont was harmed, that would be a parasitic or antagonistic relationship. And if neither benefits, that describes a neutral or no interaction.