François Jacob was a French biologist who was awarded the ‘Nobel Prize in Physiology or Medicine’ in 1965 along with another French biologist Jacques Monod and French microbiologist Andre Lwoff for their discoveries regarding genetic control of enzyme and synthesis of virus. Jacob made many significant contributions in the field of genetics by successfully collaborating with other noted scientists like Monod and Lwoff while serving the renowned ‘Pasteur Institute’ of France. His most remarkable finding was recognizing the regulator genes that regulate the activities of the structural genes. He is also known for the Jacob-Monod operon model that helps in elucidating the way genes are controlled. They elucidated on the effects of balance and imbalance between regulator genes and structural genes in a normal cell. They also examined messenger ribonucleic acid (mRNA), which convey genetic information from the deoxyribonucleic acid (DNA) – carrier of genetic instructions to the ribosome – the protein synthesizer of the cell. He showed that similar standards with regard to natural preference and evolution are followed by bacteria as done by other higher organisms. He was awarded ‘Grand Prix Charles-Leopold Mayer’ in 1962 by ‘Académie des Sciences’. In 1973 he was elected as a ‘Foreign Member of the Royal Society’ (‘ForMemRS’).

He joined the renowned ‘Pasteur Institute’ of France in 1950 as a research assistant and began working under French microbiologist Dr. André Lwoff. The following year he received his science degree.
His work centred on the genetic mechanisms present in bacteriophages and bacteria as also with regard to the biochemical effects of mutations. He examined properties of lysogenic bacteria and showed their immunity.
In 1954 he earned his PhD. in science from the ‘University of Paris’ (Sorbonne) submitting his thesis on ‘Lysogenic bacteria and the provirus concept’. The same year he started collaborating with French microbial geneticist, Elie Wollman and examined the relation between the genetic substance of bacteria and prophage. The investigation resulted in defining the mechanics of unification of bacteria as also facilitated a research of the genetic device of the bacterial cell. The work led to a number of new concepts like the procedure of genetic transfer from male to female and the episome concept. A summary of this work was given by him in the book ‘Sexuality and the Genetics of Bacteria’, which was published in 1961.
In 1956 he was made the Laboratory Director at the ‘Pasteur Institute’ and after a few years in 1960 he became the Head of the Department of Cell Genetics, a position which was created sometime recently.
In 1961 Jacob along with Jacques Monod investigated on the mechanics that are responsible for genetic data transfer and the controlling pathways present in bacterial cell that regulate the activities and synthesis of macromolecules. The duo suggested a number of new concepts like those of allosteric proteins, regulator genes and messenger RNA.
Jacob and Monod became reputed for their work on E.coli Lac operon that encodes protein required for the transfer and breakdown of sugar lactose. The duo displayed a model that showed the way levels of some of the cell proteins are regulated. According to their model the formation of proteins is restricted when a repressor that is a DNA- or RNA-binding protein, put into code by a regulatory gene, binds to a segment of DNA i.e., its operator.
The findings of Jacob and Monod convey that the balance between regulator genes and structural genes in a normal cell allows it to adjust in varying conditions while an imbalance can result in production of new enzymes which can be either favourable or harmful for the cell.
In 1962 he became a foreign member of the ‘Danish Royal Academy of Arts and Sciences’.
Along with South African biologist Sydney Brenner, he came up with the ‘replicon’ hypothesis in 1963 to detail a few facets of bacterial cell division. From that time he dedicated himself to the genetic study of the mechanics of cell division.
In 1964 he was inducted as a Professor at the prestigious higher education and research establishment ‘Collège de France’. A chair of cell Genetics was created there for Jacob. That year he also became a foreign member of the ‘American Academy of Arts and Sciences’.
In 1969 he became a foreign member of the ‘American Philosophical Society’ and also the ‘National Academy of Sciences’ of the US.
From 1970 he investigated cultured cells of mammals, especially some of the facets of the genetic properties of cells. He published a book ‘La logique du vivant, une Histoire de l'Hérédité’ (‘The Logic of Life: A History of Heredity’) in 1970 that showed the steps and phases in the study of living beings starting from the sixteenth century thereby leading to the area of molecular biology.
He was conferred honorary degrees by many universities.

He was born on June 17, 1920, Nancy, France, to Thérèse (Franck) Jacob and his wife Simon as their only child. His father was a "conformist in religion", while his mother and other close family members were secular Jews.
When he was seven-year-old he joined the public secondary and higher education school ‘Lycée Carnot’ in Paris and studied there for ten years.
As a child he looked up to his maternal grandfather Albert Franck, a four-star general. Jacob became an atheist some time after his bar mitzvah.
After completing school education he enrolled at the Faculty of Paris with the objective of becoming a surgeon and studied medicine. However his studies were interrupted during the ‘Second World War’ in 1940 when the German Army invaded France.
While in his second year of studies he fled to England in a boat in June 1940 and joined the ‘Free French Forces’ in London. Jacob was relocated to Africa where he served as a medical officer and witnessed several actions in Libya, Tunisia, Tripolitania and Fezzan.
In 1944 while stationed with the French ‘2nd Armoured Division’ in Normandy he got wounded in a German air attack and had to return to Paris on August 1 that year. He remained hospitalized for 7 months.
He received the French Order ‘Cross of Liberation’ conferred to brave hearts of the ‘Liberation of France’ during the ‘Second world War’. He also received the highest French Order ‘Légion d'honneur’ and the French military decoration ‘Croix de guerre’.
Post war he continued with his medical studies in Paris and started examining tyrothricin and studying procedures of bacteriology. In 1947 he earned his M.D. after submitting his doctoral thesis on effectiveness of antibiotics in combating local infections. However due to his wartime injuries he was unable to pursue his career as a surgeon.

He married pianist Lise Bloch in 1947. They were blessed with three sons and one daughter. Their four children were Pierre (born in 1949); Odile and Laurent (born in 1952) and Henri (born in 1954). His wife Lise died in 1983.
In 1999 Jacob married for the second time to Geneviève Barrier.
On April 19, 2013, he died in Paris, France, at the age of 92 survived by his second wife Geneviève and four children from his first marriage.

In 1965 he received the ‘Nobel Prize in Physiology or Medicine’ together with Jacques Monod and Andre Lwoff.