A linear structure in the nucleus of the cell that contains genetic material (DNA). Chromosomes are inherited in pairs, one from each parent. Two sex chromosomes, X and Y, determine the sex of an animal. An XX animal will be female and an XY animal is male. Cattle have 30 pairs of chromosomes (n = 60 total), 29 paired autosomal chromosomes and two sex chromosomes. Humans have 23 pairs of chromosomes (n = 46 total, 22 paired plus two sex chromosomes).