Short Answer

DNA was first discovered by Friedrich Miescher in the year 1869. He identified a new substance inside the nucleus of white blood cells and named it nuclein. This discovery laid the foundation for understanding genetic material.

Later, many scientists contributed to the study of DNA. James Watson and Francis Crick are credited with discovering the double helix structure of DNA in 1953, which explained how genetic information is stored and passed on.

Detailed Explanation :

Discovery of DNA

The discovery of DNA was not the work of a single scientist but the result of contributions made by several scientists over many years. However, the first discovery of DNA is credited to Friedrich Miescher, a Swiss scientist.

In 1869, Friedrich Miescher was studying white blood cells obtained from pus on surgical bandages. During his research, he isolated a new substance from the nucleus of these cells. This substance was different from proteins and had unique chemical properties. Miescher named this substance nuclein because it was found in the nucleus.

At that time, scientists did not know the importance of nuclein. Miescher himself did not realize that he had discovered the genetic material of life. However, his discovery was very important because it was the first time DNA was identified as a separate biological molecule.

Later, scientists found that nuclein contained phosphorus and was acidic in nature. Because of these properties and its location in the nucleus, nuclein was later renamed nucleic acid, which we now call DNA.

After Miescher’s discovery, many scientists began studying DNA to understand its role in heredity. For a long time, proteins were believed to be the genetic material because they were more complex. DNA was considered too simple to store genetic information.

Contribution of Other Scientists

In the early 20th century, several experiments helped prove that DNA is the genetic material. Scientists like Frederick Griffith, Oswald Avery, Colin MacLeod, and Maclyn McCarty showed that DNA carries hereditary information. These studies shifted scientific focus from proteins to DNA.

Later, Erwin Chargaff studied the chemical composition of DNA. He discovered that the amount of adenine is equal to thymine and the amount of guanine is equal to cytosine. These findings are known as Chargaff’s rules. His work provided important clues about the structure of DNA.

Discovery of DNA Structure

Although DNA was discovered by Miescher, its structure was discovered later. In 1953, James Watson and Francis Crick proposed the double helix model of DNA. This discovery explained how DNA stores genetic information and how it can copy itself.

Watson and Crick used data from several scientists. One of the most important contributors was Rosalind Franklin, who took clear X-ray diffraction photographs of DNA. Her famous photograph provided strong evidence of the helical structure of DNA.

Another scientist, Maurice Wilkins, also worked on X-ray studies of DNA and shared his data with Watson and Crick. Using all this information, Watson and Crick built a model showing that DNA consists of two strands twisted around each other in a double helix shape.

This model explained base pairing and how genetic information is passed from one generation to the next. The discovery of DNA structure is considered one of the greatest scientific achievements of the 20th century.

Importance of the Discovery

The discovery of DNA and its structure completely changed biology. It helped scientists understand heredity, variation, evolution, and many biological processes. It also led to advances in genetics, medicine, forensic science, and biotechnology.

Today, DNA research is used in genetic testing, disease diagnosis, criminal investigations, and development of new treatments. All these advancements started with the discovery of DNA by Friedrich Miescher and were expanded by later scientists.

In simple words, Friedrich Miescher discovered DNA, and Watson and Crick discovered its structure. Both discoveries are equally important in the history of biology.

Conclusion

DNA was first discovered by Friedrich Miescher in 1869, when he identified a new substance in the nucleus of cells. Later, Watson and Crick explained its double helix structure. The combined work of many scientists helped establish DNA as the genetic material of life.