The reason for the double helical structure of DNA is due to the presence of

Options

A. van der Waals' forces
B. dipole-dipole interactions
C. hydrogen bonding
D. London forces

Answer

**Step-by-Step Text Solution:**

1. **Understanding DNA Structure**: DNA (Deoxyribonucleic acid) is known for its double helical structure, which was first described by scientists James Watson and Francis Crick. This structure consists of two strands that wind around each other.

2. **Components of DNA**: The DNA molecule is made up of four nitrogenous bases: adenine (A), thymine (T), guanine (G), and cytosine (C). These bases pair specifically: adenine pairs with thymine, and guanine pairs with cytosine.

3. **Base Pairing and Hydrogen Bonds**: The connection between the two strands of DNA is primarily due to the base pairing. Adenine and thymine are held together by two hydrogen bonds, while guanine and cytosine are connected by three hydrogen bonds.

4. **Role of Hydrogen Bonds**: The hydrogen bonds between the base pairs are crucial for maintaining the stability of the double helix structure. They allow the two strands to be held together while still allowing for the strands to separate during processes like DNA replication.

5. **Conclusion**: The double helical structure of DNA is primarily due to the presence of hydrogen bonds that form between the nitrogenous bases of the two strands.

**Final Answer**: The reason for the double helical structure of DNA is due to the presence of hydrogen bonds.

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