Question

which of these pairs of organisms provides the best example of mutualism
a. the remora fish attaches to the body of a shark, gaining shelter, transportation, and leftover bits of food. the shark is neither harmed nor aided by the remora fish.
b. the desert yucca plant can reproduce because it is pollinated by the yucca moth. the yucca moth depends on the yucca plant to provide shelter and food for its larvae.
c. the brown pelican and the herring fish are both part of a beach ecosystem. the pelican eats the herring fish.
d. the tapeworm gains shelter and nutrition from the intestines of a dog. the dog is harmed because it cannot absorb as many nutrients.

Explanation:

Mutualism is a symbiotic relationship where both organisms benefit. In option B, the desert yucca plant and the yucca moth have a mutualistic relationship. The plant needs the moth for pollination to reproduce, and the moth depends on the plant to provide shelter and food for its larvae. This shows a clear mutual benefit.
Option A is a commensalism (one benefits, the other is neither helped nor harmed). Option C is a predator - prey relationship (pelican eats herring fish). Option D is a parasitic relationship (tapeworm benefits at the dog's expense).

Answer:

B. The desert yucca plant can reproduce because it is pollinated by the yucca moth. The yucca moth depends on the yucca plant to provide shelter and food for its larvae.