Question

which of the following is an example of commensalism?
barnacles attach to whales and get a place to live, but the whale gets nothing from the interaction.
the nile crocodile gets its teeth cleaned by a plover bird and the plover gets a meal from the bacteria that live on the crocodiles teeth.
roundworms live in the intestines of animals, stealing nutrients and infecting the digestive system.
lions hunt and prey on zebra populations in the savanna.
question 5 of 5

Explanation:

To determine the example of commensalism, we recall that commensalism is a symbiotic relationship where one organism benefits and the other is neither helped nor harmed.

• For the option "Barnacles attach to whales and get a place to live, but the whale gets nothing from the interaction": Barnacles benefit (get a place to live) and whales are unaffected. This fits commensalism.
• "The nile crocodile gets its teeth cleaned by a plover bird and the plover gets a meal from the bacteria that live on the crocodiles teeth": This is mutualism (both benefit).
• "Roundworms live in the intestines of animals, stealing nutrients and infecting the digestive system": This is parasitism (one benefits, the other is harmed).
• "Lions hunt and prey on zebra populations in the savanna": This is predation, not symbiosis.

Answer:

A. Barnacles attach to whales and get a place to live, but the whale gets nothing from the interaction.