Which of the following characteristics do commensalism, mutualism, and pathogenicity have in common?

• A. They all result in harm to at least one species involved.
• B. They all require the exchange of nutrients between species.
• C. They all involve interactions between different species.
• D. They all provide benefits to both interacting species.

Answer: (C)

Verified step by step guidance

1. Step 1: Begin by defining the three ecological relationships mentioned in the problem: commensalism, mutualism, and pathogenicity. Commensalism is a relationship where one species benefits while the other is neither harmed nor helped. Mutualism is a relationship where both species benefit. Pathogenicity involves one species causing harm to another.
2. Step 2: Analyze the first option: 'They all result in harm to at least one species involved.' This is incorrect because commensalism does not harm either species, and mutualism benefits both species.
3. Step 3: Evaluate the second option: 'They all require the exchange of nutrients between species.' This is incorrect because not all interactions involve nutrient exchange. For example, pathogenicity may involve harm without nutrient exchange.
4. Step 4: Consider the third option: 'They all involve interactions between different species.' This is correct because commensalism, mutualism, and pathogenicity all describe relationships between two or more different species.
5. Step 5: Assess the fourth option: 'They all provide benefits to both interacting species.' This is incorrect because pathogenicity harms one species, and commensalism does not benefit both species.