DNA molecule is the genetic material in which differences in amounts of the compounds adenine, thymine, guanine and cytosine determines the characteristic of the organism.
However, before it was identified as the molecule of heredity, the scientists were greeted with skepticism until further findings showed that DNA really is the molecule of heredity. In 1869, Johann Friedrich Miescher found out about a substance with weak acid properties and unknown function in the nuclei of human leukocytes.Studies recorded in 1924 showed that DNA and protein are both present in chromosomes. Franklin Griffith discovered in 1928 that genetic information from heat-killed bacteria cells can be transferred to live cells through the process known as transformation.
This showed that the chemical is heat-stable. In 1944, Oswald Avery, Maclyn McCarty and Colin MacLeod identified the transforming chemical as DNA but many scientists were skeptical since the molecule is too simple to be the genetic material.However, Erwin Chargaff proved in 1949 that DNA is the long-sought genetic material in his report showing that DNA composition is species-specific. He also added that DNA has equal amount of adenine and thymine as well as the amount of guanine and cytosine. James Watson and Francis Crick discovered the molecular structure of DNA in 1953 by identifying X-ray diffraction patterns—a method discovered in 1912 by Physicist Sir William Henry Bragg, and his son, Sir William Lawrence Bragg that helped determine the atomic structure of different crystals.The discoveries above had convinced the scientific community that DNA is the molecule of heredity.
In my part, I am convinced because actual experiments would show the same result for DNA. Indeed, DNA carries hereditary information. After all, knowing the history and science of DNA is important since they provide factual evidences that would prove that DNA is the molecule of heredity. Furthermore, these evidences can be proved by repeating the experiment. In modern biology, understanding the behavior and characteristics of DNA is essential in the progress of biotechnology.
