Question

A type of mutualistic relationship in which individual of one species lives in close association with individual of another species is called

• A. Symbiosis
• B. Parasitism
• C. Syntrophism
• D. Commensalism

Hint:

Symbiosis = "Living Together".
Mutualism = Both benefit (+/+).
Syntrophism is common in anaerobic environments (e.g., methanogens and fermenters).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
Ecology defines various interactions between different species.
The question asks for a term describing a close association where at least one species benefits, often used broadly to encompass mutualism.

Step 2: Detailed Explanation:

• Concept of Symbiosis: Derived from the Greek words for "living together," Symbiosis was defined by Heinrich Anton de Bary in 1879 as the "living together of unlike organisms."

• Terminology: Although modern ecology sometimes uses "symbiosis" as an umbrella term for mutualism (+/+), commensalism (+/0), and parasitism (+/-), in many biological contexts, it specifically highlights the "close association" part of the definition.

• Other Options:
- Parasitism: One organism (parasite) benefits at the expense of the host.
- Commensalism: One benefits while the other is unaffected.
- Syntrophism: A type of metabolic association where one organism depends on the presence of another to provide nutrients or remove inhibitory products (cross-feeding).

• Rationale: Since the question describes a "mutualistic relationship" (both benefit) within a "close association," Symbiosis is the most appropriate foundational term.

Step 3: Final Answer:
The term describing two species living in close, often mutually beneficial association is Symbiosis.