Question

Double helical structure of DNA was proposed by
A. Kornberg
B. Nirenberg
C. Watson and Crick
D. Wilkins and Franklin

Answer 1

Hint: Double helical structure is the structure formed by double stranded molecules of nucleic acid like DNA. A DNA molecule having two strands looks like a twisted ladder. Each strand consists of deoxyribose and phosphate groups. This double helical structure is made up of polynucleotide chains. These chains are coiled with the same axis and run alongside to form a double helix structure. These polynucleotide chains are complementary with each other.

Complete explanation:
Option A: Kornberg discovered the DNA polymerase. It is an enzyme and it participates in DNA replication. So DNA polymerase also known as the Kornberg enzyme. It repairs the synthesis of damaged DNA. DNA polymerase is the enzyme that creates the DNA molecules by the assembly of nucleotides. Option A is incorrect.
Option B: Nirenberg discovers the triplet. It is the sequence of the three bases of DNA and it codes for one or twenty amino acids. This is the building block of protein. He discovers the breaking of the genetic code and how it operates in the protein synthesis. For one amino acid three bases of DNA are presented and it was discovered by him. Option B is incorrect.
Option C: Watson and Crick used X-ray crystallography to find the helical structure of DNA. They proposed that each DNA molecule is made by two nucleotide pairs of chain that encodes the genetic information. This genetic information is available in all living beings at the DNA. They get the Nobel Prize for discovering this structure of DNA. Option C is correct.
Option D: Wikins and Franklin discover the X-Ray diffraction images of DNA. By using this X-Ray image Watson and crick proposed that DNA has helical structure. So they shared the Nobel Prize for finding the DNA structure. Option D is incorrect.

Therefore, Option C is the correct answer.

Note:
DNA is the unique structured molecule that copies itself during cell division. During cell division the cell is prepared to divide, then the helix structure splits in the middle and becomes two single strands. This single strand is the reason for producing the new two double stranded molecules. It is the replica of the original DNA molecule. DNA contains the information about how the organism will survive, grow and reproduce. So it is called the information molecule.