THE DISCOVERY OF DNA
TOPIC 2 ASSESSMENT
BY ISAAC SWAIN
1860
In 1869
Johannes
Friedrich
Miescher
was the first
rscientist to
isolate
nucleic acid
1870
1920
1900
1880
1890
1910
In 1929 Phoebus Levene
identified the
components of DNA
were linked together in
the order phosphatesugar-base to form units
which he called
nucleotides
1940
1930
TIMELINE
In 1949
Maurice
Wilkins
produced
the first
clear
image of
DNA
1950
In 1944 Erwin
Chargaff
produced
many scientific
papers about
nucleic acids
such
asOswald
DNA
In
1944
1960
In 1953 James
Watson and
Francis Crick
discovered the
double helix
structure shape
of DNA with
Rosalind
Franklins X-ray
Diffraction
Avery discovered
that DNA is the
material that
genes and
chromosomes
are made
SCIENTISTS WHO PLAYED A ROLE IN THE
DISCOVERY OF DNA
Scientist’s Specialty Area
(e.g. physicist)
Scientist’s Name
Scientist’s Country of Birth
James Watson
Chicago, USA
Francis Crick
Northampton, England
Rosalind Franklin
Notting Hill, London
Maurice Wilkins
Pongaroa, New Zealand
Erwin Chargaff
Johannes Friedrich Miescher
Czernowitz, Austria Hungary (now
Chernivsi Ukraine)
Basel, Switzerland
Physician, biologist
Oswald Avery
Halifax, Canada
Physician, medical researcher
Phoebus Levene
Sagor, Russia
Biochemist
Molecular biologist,
Geneticist, Zoologist
Molecular biologist, biophysicist
neuroscientist
Chemist
X-ray crystallographer
Biophysicist
Biochemist
JAMES WATSON
In 1953 Watson saw that the essential DNA components four organic bases must
be linked in definite pairs. This discovery was the key factor that enabled Watson
and Crick to formulate a molecular model for DNA a double helix, which can be
likened to a spiralling staircase or a twisting ladder.
FRANCIS CRICK
Francis Crick (June 8, 1916–July 28, 2004) was the co-discoverer of
the structure of the DNA molecule. With James Watson, he discovered
the double helical structure of DNA.
ROSALIND FRANKLIN
Rosalind Franklin used X-ray diffraction images which the revealed the shape
of DNA
MAURICE WILKINS
Maurice studied diffraction images and found the molecular structure of DNA,
he established the correctness of James Watsons and Francis Cricks DNA
structure
ERWIN CHARGAFF
Chargaff found that amounts of guanine, cytosine, adenine and thymine vary by
species – an indication that DNA, not protein, might be the genetic material for life.
JOHANNES FRIEDRICH MIESCHER
He was the first Scientist to discover a new living cell in the nucleus – nucleic
acid
OSWALD AVERY
He was most famous for doing an experiment that isolated DNA as the
material for which genes and chromosomes are made
PHOEBUS LEVENE
Phoebus Levene was an organic chemist in the early 1900's. He is perhaps best known for his incorrect
tetranucleotide hypothesis of DNA.