On cooling the two separated strands of DNA again recoil. It is called

Options

A. Chain reaction
B. annealing
C. both (1)&(2)
D. palindrome

Answer

To answer the question "On cooling, the two separated strands of DNA again recoil. It is called," we need to understand the process involved in DNA replication and the specific terminology used in molecular biology.

### Step-by-Step Solution:

1. **Understanding DNA Structure**: DNA consists of two strands that are complementary to each other and held together by hydrogen bonds between the nitrogenous bases.

2. **Denaturation**: When DNA is heated, the hydrogen bonds break, causing the two strands to separate. This process is known as denaturation.

3. **Cooling the DNA**: When the temperature is lowered after denaturation, the separated strands of DNA begin to cool down.

4. **Recoil of DNA Strands**: As the temperature decreases, the complementary strands of DNA start to come back together. This process of the strands rejoining is referred to as "annealing."

5. **Conclusion**: Therefore, the correct term for the process of the two separated strands of DNA recoiling upon cooling is "annealing."

### Final Answer:
The process is called **annealing**.

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