The three ways by which chromosomal theory of inheritance differ from Mendel pea experiments are- (i) Mendel concluded that genes exists in pairs and are inherited from both the parents. Chromosomal theory suggest that chromosomes contain the hereditary material. (ii) Mendel does not talk about chromosomes and meiosis whereas Sutton and Boveri explain about the different genes are present in different chromosomes. (iii) Sutton and Boveri also explains about segregation and pairing of chromosomes, which was not explained by Mendel.