Cylindrical shaped bundles of DNA in the cell nucleus (the core or center of a cell). They consist of long, threadlike strands of DNA coiled upon themselves many times. Humans have 46 chromosomes in each cell; they inherit 23 from their mother and 23 from their father. The only exceptions are sperm and egg cells which contain just 23 chromosomes each. Genes are located on the DNA which is packaged into the chromosome ‘bundles’.