Cells in production of germ cells such as pollen undergo a very different kind of division, Meiosis. Meiosis differs from mitosis in twofundamental respects:1)in meiosis there are two rounds of chromosome segregation for one round of synthesis so each germ cell receives only one of the two homologous chromosomes and 2)in meiosis the homologs pair with one another then move to opposite poles. Chromosomes behave in meiosis the same way that Mendel showed genes to behave. Each germ cell receives only one of the two homologs,a behavior that is analogous to gene segregation. The relative alignment of chromosomes is arbitrary which is analogous to independent assortment of genes. What was needed to show that genes are on chromosomes was a chromosome that could be identified in the microscope and that carried an allele for a trait that could also be followed.The proof for chromosome theory would then depend on correlating the segregation of the trait with segregation of the chromosome. T.H.Morgan proved chromosome theory in 1910 using Drosophila. Flies normally have brick-red eyes.The first white-eyed mutant was found by Morgan's wife,Lillian,who worked in the lab. white Ox red (wild type) F all red ↓ F2:3 red:1 white(but only males) Thus,the white mutation behaves like a recessive allele,but there was something unusual about the white mutation because only the male flies in the F2 have white eyes.Cells in production of germ cells such as pollen undergo a very different kind of division, Meiosis Meiosis. Meiosis differs from mitosis in twofundamental respects: 1) in meiosis there are two rounds of chromosome segregation for one round of synthesis so each germ cell receives only one of the two homologous chromosomes and 2) in meiosis the homologs pair with one another then move to opposite poles. Chromosomes behave in meiosis the same way that Mendel showed genes to behave. Each germ cell receives only one of the two homologs, a behavior that is analogous to gene segregation. The relative alignment of chromosomes is arbitrary which is analogous to independent assortment of genes. What was needed to show that genes are on chromosomes was a chromosome that could be identified in the microscope and that carried an allele for a trait that could also be followed. The proof for chromosome theory would then depend on correlating the segregation of the trait with segregation of the chromosome. T.H. Morgan proved chromosome theory in 1910 using Drosophila. Flies normally have brick-red eyes. The first white-eyed mutant was found by Morgan’s wife, Lillian, who worked in the lab. white O x red O (wild type) ↓ F1: all red ↓ F2: 3 red : 1 white (but only males) Thus, the white mutation behaves like a recessive allele, but there was something unusual about the white mutation because only the male flies in the F2 have white eyes