Question

Nucleic acids were discovered by
A. Watson and Crick
B. Khorana
C. Wilkins
D. Miescher

Answer 1

Hint: Nucleic acids are biomolecules essential to the life of all living organisms and function to store information and transfer the same to the offspring. They are found in the cells of prokaryotes and eukaryotes. The nucleic acids are composed of repeating units called nucleotides. The most commonly found nucleic acids are DNA and RNA.

Complete answer:
Option (a) is incorrect. Watson and Crick are scientists who proposed the double helical structure of DNA. Watson, crick and Wilkins were awarded the Nobel Prize in Physiology or Medicine in 1962 for the paper they published on DNA structure.
Option (b) is incorrect. Har Gobind Khorana was an Indian American scientist. He studied and researched on the ordering of nucleotides in the nucleic acid molecules. Along with Marshall Nirenberg and Holly, he shared the Nobel Prize in Physiology or Medicine in 1968 for the same.
Option (c) is incorrect. Maurice Wilkins proposed the double helical structure of DNA along with Watson and Crick. The three scientists shared the Nobel Prize in Physiology and Medicine in 1962 for the same.
Option (d) is correct. Friedrich Miescher was the first biologist to isolate and study DNA. His research led to the discovery of phosphate rich molecules, that he named nuclein. Miescher used white blood cells for his research and isolated the nuclein from their nuclei. The molecule nuclein later was identified as DNA. We can therefore conclude that it was this piece of research that led to further studies and subsequent identification of double helical structure of DNA and its role in inheritance.

Hence, the correct answer is option (D).

Note: Friedrich Miescher isolated DNA from the nucleus of white blood cells. He called the molecules nuclein. The results of his studies were first published in 1871. He also proposed that the nuclein might be related to inheritance in living beings. These studies paved the way for further research in this field.