Francis Crick and James Watson Quiz

Francis Crick

• Crick was a British biophysicist who won the Nobel Prize for his co-discovery of the structure of DNA in 1953.
• He studied physics at University College London and worked for the Royal Navy during World War II.
• He later returned to Cambridge to pursue a PhD in biological sciences.
• He collaborated with James Watson at the Cavendish Laboratory in Cambridge.
• They unveiled DNA’s molecular structure together.
• He played a vital role in deciphering the structure of DNA.
• Crick focused on the genetic code and its role in molecular biology.
• He described the genetic code as "the key to molecular biology" in 1966.
• He moved to California in 1976 to study developmental neurobiology and human consciousness.

James Watson

• American geneticist and biophysicist who shared the Nobel Prize for his co-discovery of the double helix structure of DNA.
• He studied zoology at the University of Chicago.
• Watson completed his PhD in virus research.
• He moved to the Cavendish Laboratory in Cambridge, where he met and collaborated with Francis Crick.
• He returned to the Cavendish Laboratory to work with Crick on virus construction.
• He lectured at Harvard and became a biology professor.
• He wrote key biological texts.
• He led the international Human Genome Project in 1989, to map all the genes of a human chromosome.

DNA: A Remarkable Discovery

• The discovery of DNA's double helix structure revolutionized scientific understanding of heredity.
• DNA, or deoxyribonucleic acid, is the chemical substance within cells that determines hereditary patterns in all living things.
• Understanding DNA's structure led to understanding how it replicates and transmits genetic information.
• This provided crucial insight into how genes operate.

The Race to Discover DNA's Structure

• The discovery of DNA's double helix was the culmination of years of research by many scientists.
• Oswald Avery's research in 1944 showed that DNA carries genetic information but didn't fully delineate the precise structure.
• The race to uncover DNA's structure led to significant advancements in scientific methods, including gene sequencing and genetic engineering.

Sydney Brenner and the Discovery of DNA

• Sydney Brenner is a South African biologist who made crucial contributions to uncovering DNA's structure.
• Brenner completed his PhD at Oxford University.
• He conducted leading research in developmental genetics and molecular biology.
• Brenner’s work on organ development and cell apoptosis earned him a Nobel Prize in 2002.
• His 18 months of research led to a groundbreaking single-page paper on the DNA model.
• He completed a model of DNA in 3 days.

Unraveling the Secret of DNA

• Scientists struggled to determine DNA structure and replication until the 1950s.
• Linus Pauling, Rosalind Franklin, and Maurice Wilkins at King's College London played important roles, but did not fully understand DNA's structure.
• They understood that DNA had a backbone of phosphoric acid and sugar and four bases: adenine, thymine, guanine, and cytosine.
• It wasn't until the efforts of Francis Crick and James Watson that the structure of DNA was finally understood.

DNA Structure

• Rosalind Franklin’s X-ray photograph (Photograph 51) showed DNA's double helix structure.
• Franklin worked alongside Maurice Wilkins, and Wilkins showed Photograph 51 to Crick and Watson without Franklin’s knowledge.
• This image helped Crick and Watson confirm the double helix structure and complete their model.
• The DNA double helix resembles a twisted ladder, with the phosphoric acid and sugar strands forming the uprights of the ladder.
• Paired bases (A, T, C, and G) create the rungs of the ladder.
• The order of these bonded bases forms the genetic code.
• When the ladder splits, each half bonds with newly formed DNA components to create two new, identical double helix structures

Rosalind Franklin

• British chemist whose X-ray diffraction images were crucial to determining the double helix structure of DNA.
• Franklin studied the structure of coal and graphite.
• Franklin specialized in X-ray crystallography and used it to study the structure of DNA.
• Franklin’s image helped Watson and Crick confirm the double helix structure of DNA, but her contributions were not fully recognized during her life.

Maurice Wilkins

• British biophysicist who shared the Nobel prize for his X-ray diffraction studies of DNA.
• He used X-ray imaging to study DNA fibers.
• He was part of the King's College, London research team working on DNA structure.

The Nobel Prize in Chemistry and DNA Sequencing

• Frederick Sanger was the first person to win two Nobel Prizes in Chemistry.
• Sanger received the first in 1958 for his work on insulin.
• He developed a method for DNA sequencing using radioactive isotopes to "label" fragments.
• He tracked overlaps between fragments to build up the complete sequence.
• His team developed a method for isolating DNA fragments quickly by using a molecule inhibitor to prevent DNA strands from extending and ordering the strands from shortest to longest to identify the base order.
• He helped sequence the first human genome in 1981.

John Sulston and the Worm

• The first director of the Wellcome Sanger Institute.
• Won the 2002 Nobel Prize for his work with the nematode worm (C.elegans).
• His research contributed to the understanding of cell division, differentiation, and death.
• He helped sequence the first animal genome.

Key Dates

• 1953: Crick and Watson's DNA double-helix discovery.
• 1958: Sanger's first Nobel Prize for work on insulin.
• 1950s: Franklin studied the crystalline structure of viruses including polio.
• 1967: Sanger's RNA sequencing.
• 1977: Sanger's dideoxy chain-termination method for sequencing DNA, still used today
• 1981: First human mitochondrial genome sequenced.
• 1988: First animal genome sequenced (C.Elegans).
• 1990-2003: The Human Genome Project.

Additional information

• 51 took 60 hours to produce.
• Franklin received a $13,000 grant for her polio virus study.
• She bequeathed $4,000 to support Aaron Klug in his work.