Question

Diameter of DNA is/Wilkin’s X-ray diffraction showed DNA diameter to be
A. $200$Å
B. $100$Å
C. $20$Å
D. $50$Å

Answer 1

Hint: DNA is deoxyribonucleic acids. DNA is the genetic material in most of the living organisms. DNA is a double helix structure was given by Waston and Crick. The scientist Maurice Wilkins uses the technique of X-ray crystallography to determine the structure of DNA molecules.

Complete answer:
X-ray crystallography is a biophysical technique. In this technique, the molecules are used in the form of crystal to determine the structure and then exposed to X-ray on them. The X-ray deflected from the crystal and made diffraction patterns. These patterns are used to reconstruct the structure of molecules.
Maurice Wilkins used in this technique to find out the structure of the DNA molecule. From his experiment, he concluded that the diameter of DNA is $20$ Å.
Therefore the correct answer is option C, that is, $20$Å.

Additional information: When we look back at the history of DNA structure, the first name that came in our mind is Waston and Crick. They proved that the DNA is a double-helical structure. But there are Maurice Wilkins and Rosalind Franklin who contributed to the history of DNA. The ‘image $51$’ that is Franklin’s crystallography image of DNA gave important clues for Waston and Crick to determine the structure of DNA. In $1953$ Waston and Crick with the help of X-ray diffraction images proposed the famous double helix structure of DNA.

Note: The DNA’s length is determined by the number of nucleotides/base pairs present in it. The base pairs are different in different organisms. For examples, bacteriophages have $48502$ bp whereas E.coli has $4.6 \times {10^9}$ bp. The human has $6.6 \times {10^9}$ bp. The DNA is genetic material almost in all the living beings. There are other organisms which have RNA as genetic material.