Question

Who discovered DNA ?
1. Gergor Mendel
2. James Watson and Francis Crick
3. Johannsen
4. Hargovind Khorana

Answer 1

Correct Answer - Option 2 : James Watson and Francis Crick

The correct answer is James Waston and Francis Crick.

• American biologist James Watson and English physicist Francis Crick discovered DNA in the 1950s.
• DNA is a long molecule that contains a unique genetic code.
  • It holds the instructions for making all the proteins in our bodies and the function of living things.

• In the cell nucleus, the DNA molecule is packaged into thread-like structures called chromosomes.
  • A chromosome (microscopic structure) is made up of DNA tightly coiled many times around proteins called histones that support its structure.
  • A chromosome has two arms - p arm (short arm) and q arm (long arm), joined in the location of the centromere.
• The information in DNA (double helix structure) is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
  • DNA has two base pairs, A-T and G-C, attached to a sugar-phosphate backbone.

Gregor Mendel	Father of modern genetics. He discovered the fundamental laws of inheritance through his work on pea plants Mendel's laws of inheritance include the law of dominance, law of segregation, and law of independent assortment.
Johannsen	He first proposed the distinction between genotype and phenotype in the study of heredity. Pure Line Theory was proposed by Johannsen based on his studies with beans (Phaseolus vulgaris) variety called Princess. A pure line is the progeny of a single self-fertilized homozygous plant. a group of closely related individuals of an identical genetic constitution (as the offspring of a homozygous self-fertilized parent)
Hargovind Khorana	He got the Nobel Prize in Physiology or Medicine in 1968 for his interpretation of the genetic code and its function in protein synthesis. He demonstrates the role of nucleotides in protein synthesis and helped crack the genetic code.