DNA structure, function, and biological significance

DNA

In science, evidence is necessary to prove or disprove a hypothesis. Evidence suggests DNA is the molecule of heredity. In your response, list the scientists and the work they did to convince science and society that DNA is indeed the molecule of heredity. Next, list the evidence that would convince you that DNA is the molecule of heredity. Finally, reflect on why learning about the history and science of DNA is important in learning that DNA is the molecule of heredity.

Although James D. Watson and Francis H. Crick are credited with 'discovering' DNA, the concept of heritable traits can be traced back to the monk Gregor Mendel, who first noticed regressive and dominant characteristics in the fertilization of different plants. Watson and Crick 'only' discovered DNA's double helix structure, and by the time they conducted their experiments in DNA structure, the idea that nucleic acid contained the blueprint of humanity was already widely accepted.

To a person uneducated in the scientific method, the idea of invisible substances like DNA transmitting genetic information would seem difficult to prove, as the evidence exists on the molecular level. Without the benefits of modern technology, the idea of heritable traits could not be connected to a specific, heritable entity within living beings. It was in 1943 that an American named Oswald Avery proved the hypothesis that nucleic acid, or DNA carried genetic information. "Earlier in this century, as biologists started to envision the radical variations in the structure of various proteins, they naturally suspected proteins might carry heredity" ("The Biggest Blunder," 2003, Nobel Prizefight). By purifying nucleotide DNA from donor bacteria, exposing recipient bacteria to that DNA, and allowing the recipient to divide, Avery showed that the daughter cells carried traits from the donors, thus the supposedly too simple substance DNA was the carrier of traits, not proteins. It was Avery who made the connection between DNA and heritable traits.