Important discoveries in genetics

Gegor Mendel establishes principles of genetics

Independently described the behavior of sex chromosomes-XX determines female; XY determines male.

George Beadle and Edward Tatum discover through experiments on neurospora, a bread mold, that genes are responsible for the production of enzymes. Their report is the genesis of the "one gene-one enzyme" concept.

It was discovered in 1940 that some genes can jump.

Scientists prove that DNA alone is the substance that transmits heredity, and that it has a spiraling, double-helix structure

Marshall Nirenberg leads the team that discovers the genetic code, showing that a sequence of three nucleotide bases (a codon) determines each of the 20 amino acids.

Philip Hanawalt of stanford and Richard B. of Oak Ridge National shows that DNA repairs itself

Ron Davis and Janet Mertz discover restriction endonucleases, essential for cleaving and “recombining” DNA.

In a step toward a cancer vaccine, Ronald Levy stimulates cancer patients’ immune systems with genetically engineered vaccines grown from their own tumors

It was discovered that there are 20,000 to 25,000 genes in a human body.