Which term refers to the external environment that is harmful to an organism?

• A. Biotic Factors
• B. Adverse external environment
• C. Climatic factors
• D. Biosphere

Answer: (B)

The question tests how we name harmful conditions coming from the outside environment. When the external surroundings are unfavourable or damaging to an organism, we describe them as an adverse external environment. This term captures stressors that are non-living parts of the surroundings—such as extreme temperatures, toxins, or pollutants—that can reduce growth, survival, or reproduction. It’s distinct from biotic factors, which are living components like predators or pathogens, and from climatic factors, which are weather-related abiotic conditions. The biosphere, meanwhile, is the whole system of Earth's ecosystems, not a description of harmful external conditions.