ABSTRACT
From a genetic vantage point, there are two types of cells in diploid organisms such as humans: germinal cells and somatic cells. Germinal cells consist of sperm, ova, and their precursors produced in the germline. All other cells are somatic. All somatic cells contain essentially the same two copies of the 40 000 genes or so that make up the human genome – one copy from the mother and one copy from the father of the individual. Ova and sperm cells contain only one copy. After fertilization, the zygote owns two copies, and divides to develop into a new individual, with a germline and somatic cell lines.
