DNA Basics

Who discovered DNA? What does DNA look like? What does DNA do? How does DNA replicate?

-A middle school student from Michigan

May 28, 2004

Well, at least you don't want to know a lot! We have split your questions into four separate parts (look for the other questions in our archived list). The first question will be answered here.

Who discovered DNA?

This is a tough question because it is hard to know what people mean by DNA. Do they mean genes, or the substance DNA or chromosomes or the structure of DNA or...

Here is a brief timeline of some discoveries about DNA:

1856-1865 Gregor Mendel founds genetics.

1869 Johann Friedrich Miescher discovers a weakly acidic substance in human nuclei he calls nuclein. It is later called DNA.

1882 Walther Fleming discovers chromosomes.

1902-1903 Walter Stanborough Sutton uses grasshoppers to discover that chromosomes have genes.

1924 Chromosomes are shown to be made of protein and DNA.

1928 Franklin Griffith figures out that genetic information can be transferred from heat-killed bacteria to live ones.

1944 Oswald Avery figures out that Griffith's substance was DNA.

1949 Edwin Chargaff figures out that no matter the species, the amount of adenine (A) equals the amount of thymine (T) and the amount of guanine (G) equals the amount of cytosine (C).

1953 Francis Crick, James Watson and Rosalind Franklin discover the double helix structure of DNA.

1961 Francis Crick and Sydney Brenner figure out that three bases (a codon) are needed to code for an amino acid

By Dr. Barry Starr, Stanford University