Question

DNA was first discovered by
A. Meischer
B. Robert Brown
C. Flemming
D. Watson and Crick

Answer 1

DNA serves the purpose of two most important cellular functions. It is the genetic material which passes information from parent to offspring. It acts as the information molecule to direct and regulate the making of other large molecules called proteins which are pivotal for growth, reproduction and overall health of our human body.

Complete answer:
In 1869, the Swiss physiological chemist Friedrich Miescher created a landmark in genetic research by identifying first isolated nucleic acids called nuclein inside the nuclei of human white blood cells. The main source of these cells was obtained from pus cells in discarded surgical bands. The term "nuclein" was referred to as ''nucleic acid', then later on called "DNA" or "DeoxyriboNucleic Acid". Therefore, the discovery of DNA at first was done by Meischer.
Robert Brown's experiment led to the discovery of nucleus and its functions. His invention paved a great way in proving the cell theory that all living organisms are composed of cells which come from pre-existing cells.
Discovery of Penicillin, a group of antibiotics which is used to treat bacterial infections was done by Alexander Flemming.
Watson and Crick invented the molecular structure of DNA in the form of a three-dimensional double helix based on its known features.

Hence, the correct answer is option (A).

Note: In the year 1881, Albrecht discovered that nuclein as a nucleic acid and provided its chemical name, deoxyribonucleic acid (DNA). He also identified that these acids were composed of five nucleotide bases that are considered to be the building blocks of DNA and RNA namely,
-adenine (A),
-cytosine (C),
-guanine (G),
-thymine (T)
-uracil (U).
He was awarded the Nobel Prize in Physiology or Medicine for his contribution in the field of genetics in 1910.