Which of the following is an example of an abiotic ecological factor?

Step 1: Analyze the question The question asks for an abiotic ecological factor. "Abiotic" means non-living, so we are looking for a physical or chemical part of the environment, not something that involves living organisms.

Step 2: Explain the concept Ecological factors fall into two groups:

• Abiotic factors: non-living components such as temperature, light, rainfall, humidity, soil pH, wind, salinity and topography.
• Biotic factors: the living components and the interactions between organisms, such as competition, predation, parasitism, symbiosis, and the presence of plants and animals.

Step 3: Evaluate each option

• A. Temperature: a physical property of the environment, with no living organism involved. It is abiotic.
• B. Competition: a relationship between organisms (for food, space or mates). It is biotic.
• C. Predation: one organism hunting and feeding on another. It is biotic.
• D. Symbiosis: a close living relationship between two different species (such as mutualism). It is biotic.

Step 4: Answer Only temperature is non-living, so the correct answer is A. Temperature.

Exam tip: Remember "a-biotic = no life." If an option describes an interaction between organisms (competition, predation, parasitism, symbiosis, commensalism), it is biotic. If it describes something you could measure with an instrument, such as a thermometer, rain gauge, pH meter or light meter, it is abiotic.