Many blue-green algae occur in thermal springs (hot water springs). The temperature tolerance of these algae have been attributed to their

Options

A. Mitochondrial structure
B. Importance of homopolar bonds in their proteins
C. Cell wall structure
D. Modern cell organization

Answer

**Step-by-Step Solution:**

1. **Understanding the Organism**: Blue-green algae, also known as cyanobacteria, are known for their ability to thrive in extreme environments, including thermal springs.

2. **Temperature Tolerance**: The question focuses on the temperature tolerance of these algae, particularly in high-temperature environments like thermal springs.

3. **Key Factor**: The temperature tolerance of blue-green algae is attributed to the presence of certain types of chemical bonds within their cellular structures.

4. **Homopolar Bonds**: The specific type of bond mentioned is homopolar bonds. These bonds are characterized by the equal sharing of electrons between atoms, which contributes to their stability under high temperatures.

5. **Heat Resistance**: The stability of homopolar bonds means they do not break down easily, even at high temperatures (up to 100 degrees Celsius), allowing the algae to survive in extreme conditions.

6. **Conclusion**: Therefore, the temperature tolerance of blue-green algae in thermal springs is primarily due to the presence of heat-resistant homopolar bonds in their cellular structure.

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