Which group of bacteria can grow and reproduce at cold temperatures (e.g., at or below 0–10°C)?

• A. Hyperthermophiles
• B. Mesophiles
• C. Thermophiles
• D. Psychrophiles

Answer: (D)

Verified step by step guidance

1. Understand the temperature ranges associated with different bacterial groups: Hyperthermophiles thrive at very high temperatures (above 80°C), Mesophiles grow best at moderate temperatures (around 20–45°C), Thermophiles prefer high temperatures (45–80°C), and Psychrophiles are adapted to cold environments (0–15°C).
2. Identify the temperature range given in the problem (0–10°C) and compare it to the optimal growth temperatures of each bacterial group.
3. Recognize that bacteria capable of growing and reproducing at or below 0–10°C must be adapted to cold environments, which excludes Hyperthermophiles, Mesophiles, and Thermophiles based on their temperature preferences.
4. Conclude that Psychrophiles are the group of bacteria that can grow and reproduce at cold temperatures, as they have specialized enzymes and membrane structures that function efficiently in cold conditions.
5. Summarize that the correct answer is Psychrophiles because they are uniquely adapted to thrive in cold environments, unlike the other groups listed.