Which term refers to organisms that tolerate only a narrow range of temperatures?

• A. Stenothermal
• B. Eurythermal
• C. Thermophile
• D. Psychrophile

Answer: (A)

Organisms with a narrow temperature tolerance have a limited range of temperatures in which their enzymes, membranes, and metabolism function optimally. This narrow tolerance is described by the term stenothermal. It highlights how these organisms are specialized for a specific thermal environment and may struggle outside that small range.

In contrast, eurythermal organisms can cope with a broad range of temperatures. Thermophiles are adapted to high temperatures, while psychrophiles are adapted to very cold temperatures, each representing preferences rather than narrow tolerance.