Which relationship is beneficial to both interacting organisms but is not obligatory

Options

A. commensalism
B. protocooperation
C. mutualims
D. Both B and C

Answer

To answer the question "Which relationship is beneficial to both interacting organisms but is not obligatory?", we can follow these steps:

### Step 1: Understand the Types of Relationships
First, we need to understand the different types of ecological relationships that can exist between organisms. The options provided include commensalism, proto-cooperation, and mutualism.

### Step 2: Analyze Commensalism
Commensalism is a type of relationship where one organism benefits while the other is neither helped nor harmed. For example, barnacles on a whale benefit from being transported to different feeding areas, while the whale is unaffected. This does not fit the criteria since it does not benefit both organisms.

**Hint:** Commensalism involves one organism benefiting and the other being neutral.

### Step 3: Analyze Mutualism
Mutualism is a relationship where both organisms benefit from the interaction. However, it is often obligatory, meaning that both organisms depend on each other for survival. An example is the relationship between bees and flowers, where bees get nectar and flowers get pollinated.

**Hint:** Mutualism benefits both but is often essential for survival.

### Step 4: Analyze Proto-cooperation
Proto-cooperation is a relationship where both organisms benefit, but the relationship is not obligatory. This means that both organisms can survive independently, but they gain advantages from interacting. An example is the relationship between certain fish and cleaner shrimp, where both benefit from the interaction but can live without it.

**Hint:** Proto-cooperation benefits both organisms but is not essential for their survival.

### Step 5: Conclusion
Based on the analysis of the three types of relationships, the correct answer to the question is proto-cooperation. This relationship is beneficial to both interacting organisms but is not obligatory.

**Final Answer:** The relationship that is beneficial to both interacting organisms but is not obligatory is **proto-cooperation** (Option B).