Sutton and Boveri in support of Mendel’s observations state that the carriers of genes are chromosomes. According to their theory: Homologous pair of chromosomes has the two alleles of a gene located on these homologous pairs of chromosomes at the same site. The homologous pair separates in the process of gamete formation during meiosis. Chromosomes segregate and also, assort independently. During fertilisation, gametes combine, and also the resulting offspring has the diploid no. of chromosomes that are similar to the parent. Morgan’s extensive work on Drosophila melanogaster or fruit flies gave experimental evidence to support the chromosomal theory of inheritance.