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.
X chromosome Luke Hutchison noticed that a number of possible ancestors on the X chromosome inheritance line at a given ancestral generation follows the Fibonacci sequence.[9] A male individual has an X chromosome, which he received from his mother, and a Y chromosome, which he received from his father. The male counts as the "origin" of his own X chromosome (   F 1  = 1  {\displaystyle F_{1}=1} ), and at his parents' generation, his X chromosome came from a single parent (   F 2  = 1  {\displaystyle F_{2}=1} ). The male's mother received one X chromosome from her mother (the son's maternal grandmother), and one from her father (the son's maternal grandfather), so two grandparents contributed to the male descendant's X chromosome (   F 3  = 2  {\displaystyle F_{3}=2} ). The maternal grandfather received his X chromosome from his mother, and the maternal grandmother received X chromosomes from both of her parents, so three great-grandparents contributed to the male descendant's X chromosome (   F 4  = 3  {\displaystyle F_{4}=3} ). Five great-great-grandparents contributed to the male descendant's X chromosome (   F 5  = 5  {\displaystyle F_{5}=5} ), etc. (Note that this assumes that all ancestors of a given descendant are independent, but if any genealogy is traced far enough back in time, ancestors begin to appear on multiple lines of the genealogy, until eventually, a population founder appears on all lines of the genealogy.)