Double Helix model for the structure of DNA was proposed by

Options

A. James Watson and Francis Crick
B. Maurice Wilkins and Rosalind Franklin
C. Francis Crick and Maurice Wilkins
D. Rosalind Franklin and James Watson

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who proposed the double helix model for the structure of DNA.

2. **Identifying Key Scientists**: The key scientists associated with the discovery of the DNA structure are James Watson and Francis Crick.

3. **Historical Context**: In 1953, Watson and Crick published their model of DNA, which described it as a double helix. This model was based on earlier work by other scientists, including Rosalind Franklin and Maurice Wilkins.

4. **Characteristics of the Double Helix**: The double helix structure consists of two strands of nucleotides that wind around each other. Watson and Crick's model highlighted features such as:
- The DNA is a biopolymer made of polynucleotides.
- The most common form of DNA is known as B-DNA.
- The structure is right-handed and has approximately 10 base pairs per turn.
- It includes major and minor grooves.

5. **Evaluating Options**: The options provided in the question are:
- A) James Watson and Francis Crick
- B) Maurice Wilkins and Rosalind Franklin
- C) Francis Crick and Maurice Wilkins
- D) Rosalind Franklin and James Watson

Among these, the correct answer is A) James Watson and Francis Crick, as they are credited with proposing the double helix model.

6. **Conclusion**: Therefore, the answer to the question is that the double helix model for the structure of DNA was proposed by James Watson and Francis Crick.

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