Similarities in chromosome number, banding pattern of chromosomes and DNA content of great apes (orangutan, chimpanzee, and gorilla) and man support the idea of their common ancestry. Each human cell contains 46 chromosomes, of these 44 are autosomes and 2 are sex chromosomes. However, the chromosome number is 48 for orangutan, chimpanzee and gorilla. Chromosomes are treated with specific stains to study the banding pattern. It is interesting to note that the banding pattern of the human chromosome is very similar and in a few cases identical to the banding pattern of apparently homologous chromosomes in great apes. This can be particularly noticed in the banding pattern of chromosomes 3 and 6 when human chromosomes are compared with a chimpanzee. The total amount of DNA in a human diploid cell and that of great apes is not much different. This indicates that the DNA of man is very closely related to that of apes than that of monkeys.