who proved that genes are located on chromosomes
Boveri–Sutton chromosome theory The proposal that chromosomes carried the factors of Mendelian inheritance was initially controversial, but in 1913 it gained strong support when Eleanor Carothers documented definitive evidence of independent assortment of chromosomes in a species of grasshopper.[11] Debate continued, however, until 1915 when Thomas Hunt Morgan's work on inheritance and genetic linkage in the fruit fly Drosophila melanogaster provided incontrovertible evidence for the proposal.[1][3] The unifying theory stated that inheritance patterns may be generally explained by assuming that genes are located in specific sites on chromosomes.
Hugo de Vries Hugo Marie de Vries ForMemRS[1] (Dutch pronunciation: [ˈɦyɣoː də ˈvris]; 16 February 1848 – 21 May 1935)[2] was a Dutch botanist and one of the first geneticists. He is known chiefly for suggesting the concept of genes, rediscovering the laws of heredity in the 1890s while unaware of Gregor Mendel's work, for introducing the term "mutation", and for developing a mutation theory of evolution.