Which of the following is an abiotic factor in an ecosystem?

Step 1: Analyze the question The question asks which option is an abiotic factor. "Abiotic" means non-living, so we are looking for a physical or chemical component of the environment.

Step 2: Explain the concept An ecosystem has two kinds of factors:

• Biotic factors are living things or their products. Examples are plants, animals, microorganisms, and the interactions between them, such as predation, parasitism, and competition.
• Abiotic factors are non-living physical and chemical conditions. Examples are temperature, light, rainfall, humidity, wind, soil pH, salinity, and atmospheric pressure.

Step 3: Check each option

• A. Food: This is organic matter from plants or animals, so it is biotic.
• B. Host: A host is a living organism that carries a parasite, so it is biotic.
• C. Parasite: This is a living organism, so it is biotic.
• D. Predator: This is a living animal that hunts others, so it is biotic.
• E. Pressure: This is atmospheric or water pressure, a physical condition of the environment. It is non-living, so it is abiotic.

Step 4: Answer

Tip: To spot abiotic factors, ask yourself, "Is it alive, or does it come from something alive?" If not, it is abiotic. Think of the list: temperature, light, water, wind, pressure, pH, soil type. Anything that is an organism or a relationship between organisms (host, parasite, predator, prey) is biotic.