Give one significant contribution of the scientist :
Francis Crick

Explanation

**Step-by-Step Solution:**

1. **Identify the Scientist**: The question asks for a significant contribution of Francis Crick, a prominent scientist in the field of biology.

2. **Recognize His Collaboration**: Francis Crick is best known for his collaboration with James Watson. Together, they made groundbreaking contributions to our understanding of DNA.

3. **Understand the Contribution**: Crick and Watson's most significant contribution was the discovery of the double helix structure of DNA. They proposed that DNA is composed of two strands that coil around each other, forming a helical structure.

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