Answer:
The type of relationship that exists between two organisms when one benefits but the other is neither helped nor harmed is called commensalism.
Commensalism is a symbiotic relationship where one organism benefits while the other is unaffected. In this relationship, the organism that benefits is known as the commensal, while the other organism is referred to as the host.
Examples of commensalism include:
1. Barnacles on a whale: Barnacles attach themselves to the skin of whales and benefit by gaining a stable surface to live on and access to food particles in the water. The whale is unaffected by their presence.
2. Birds nesting in trees: Birds often build their nests in trees, using branches and foliage as support. The birds benefit from the shelter and protection provided by the tree, while the tree is unharmed.
3. Remora fish and sharks: Remora fish attach themselves to sharks using a specialized suction disc on their heads. They benefit by gaining transportation, protection, and access to leftover food from the shark's meals. The shark is not significantly affected by their presence.
In summary, commensalism is a type of relationship where one organism benefits while the other is neither helped nor harmed. It is characterized by one-sided interaction without any significant negative or positive impact on the other organism.