Micro-organisms having optimum temperature for growth below `15^(@)C` which cannot grow above `20^(@)C` are called

Options

A. Mesophiles
B. Thermophiles
C. Psychrophiles
D. None of the above.

Answer

To solve the question, we need to identify the type of microorganisms based on their temperature preferences for growth. Here’s a step-by-step breakdown:

### Step 1: Understand the Temperature Ranges
- The question specifies microorganisms that have an optimum growth temperature below 15°C and cannot grow above 20°C.

### Step 2: Analyze the Options
- **Mesophiles**: These microorganisms thrive in moderate temperatures, typically between 20°C to 45°C. Since they prefer higher temperatures, they do not fit the criteria.

- **Thermophiles**: These organisms grow in high-temperature environments, usually between 41°C to 122°C. They are not suitable for the conditions described in the question.

- **Cryophiles (or Psychrophiles)**: These microorganisms are adapted to cold environments. They typically grow best at temperatures below 15°C and cannot grow above 20°C, which matches the conditions given in the question.

- **None of the Above**: This option is not applicable since we have identified a suitable category.

### Step 3: Conclusion
Based on the analysis of the options, the correct answer is **C: Cryophiles (or Psychrophiles)**, as they are the microorganisms that thrive in low temperatures below 15°C and cannot grow above 20°C.

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