DNA Structure and Discovery — Graph

What are purines, and why did Fischer's work on them turn out to matter for genetics?

How long after Kossel's work did Watson and Crick reveal what the nucleotide bases actually encode?

How did X-ray crystallography go on to reveal the structure of DNA and haemoglobin?

What later discoveries depended on the X-ray crystallography method von Laue established?

What later scientific discoveries, from penicillin to DNA's double helix, depended on Bragg's law?

What did Phoebus Levene establish about the structural backbone of DNA?
What was the tetranucleotide hypothesis and why did it suggest DNA couldn't carry genetic information?
How did Erwin Chargaff's later measurements overturn Levene's conclusion about base ratios?
How did Levene's structural work still enable Watson and Crick's model despite his mistaken conclusion?

What is bacterial 'transformation,' and why had it puzzled biochemists for two decades before 1944?
How did Avery, MacLeod, and McCarty systematically rule out other molecules to identify DNA as the transforming principle?
Why is Avery's exclusion from the Nobel Prize considered one of the most debated oversights in the prize's history?

What experiment led Avery, MacLeod, and McCarty to conclude that DNA, not protein, carries hereditary information in pneumococcal bacteria?
Why was DNA initially considered too chemically simple a molecule to encode hereditary complexity?
Why did Oswald Avery never receive a Nobel Prize despite the significance of his discovery?

What technique did Erwin Chargaff use to measure the base composition of DNA?
What exact numerical relationship did Chargaff find between adenine and thymine, and guanine and cytosine?
How did the A+T to G+C ratio vary across species even though the pairing rule held within each?
How did Chargaff's rules become a clue Watson and Crick used to work out DNA's structure?

What did Franklin's X-ray crystallography reveal about the position of the phosphate groups in DNA?
What is the difference between the A-form and B-form of DNA that Franklin identified?
How was Franklin's Photograph 51 used by Watson and Crick without her knowledge?
Why was Franklin excluded from the 1962 Nobel Prize awarded for the structure of DNA?

Why did Hershey and Chase label phage DNA with radioactive phosphorus and protein with radioactive sulphur?
How did a kitchen blender help prove that DNA, not protein, carries hereditary information?
How did the Hershey-Chase results relate to Watson and Crick's DNA structure announced the following year?

How does the base-pairing rule (adenine with thymine, guanine with cytosine) suggest a mechanism for copying genetic material?
What role did Rosalind Franklin's X-ray diffraction images play in Watson and Crick's model, and why has that contribution been contested?
Why was Rosalind Franklin excluded from the 1962 Nobel Prize awarded for the DNA structure?
What modern technologies, from forensic databases to mRNA vaccines, trace their origin back to the double-helix model?

Why does understanding the nucleotide linkage matter for both cellular energy transfer and DNA's structure?

What did Watson and Crick's double helix model predict about how DNA copies itself?

How did von Laue's X-ray crystallography technique later contribute to determining the structure of DNA?

How did Schrödinger's 1944 book What Is Life? influence Francis Crick's move into biology?

How does DNA's base-pairing rule let each strand of the double helix act as a template for copying the other?
What role did Rosalind Franklin's X-ray diffraction images play in Watson and Crick's model, and why has that role remained contested?
Why was Rosalind Franklin ineligible for a share of the 1962 Nobel Prize?
What did the double helix model explain that earlier proposed structures of DNA could not?

What did Crick and Watson determine about the structure of DNA in 1953, and whose data helped them get there?
What problem did Crick turn to studying after his work on DNA, in his later years at the Salk Institute?
How did Crick's training as a physicist shape his approach to biology?