This document describes the chromosomal theory of inheritance proposed by Sutton and Boveri in 1903. They concluded that chromosomes contain genes which govern the transmission of characters from parents to offspring, establishing chromosomes as the physical basis of inheritance. The theory was supported by evidence including sex chromosomes, sex linkages, and structural chromosomal changes observed through experiments in grasshoppers. The document then provides details about cell division, the cell cycle, mitosis, meiosis, and compares the key differences between mitosis and meiosis.