Which of the following environments is most likely to harbor a thermophilic microorganism?

• A. Human skin
• B. Freshwater lakes at room temperature
• C. Hot springs with temperatures above 60 ^ext{o}C
• D. Arctic ice sheets

Answer: (C)

Verified step by step guidance

1. Understand the definition of thermophilic microorganisms: these are microbes that thrive at relatively high temperatures, typically between 45°C and 80°C or higher.
2. Analyze each environment given in the problem and consider its typical temperature range: Human skin is around 33-37°C, freshwater lakes at room temperature are about 20-25°C, hot springs can exceed 60°C, and Arctic ice sheets are well below 0°C.
3. Recall that thermophiles require elevated temperatures to grow optimally, so environments with temperatures significantly above normal ambient conditions are suitable habitats.
4. Compare the temperature ranges of the options to the optimal growth temperature range of thermophiles, identifying which environment matches or exceeds 45°C.
5. Conclude that hot springs with temperatures above 60°C provide the ideal conditions for thermophilic microorganisms to thrive, unlike the other cooler environments listed.