A common feature of centromeric DNA studied so far is the presence of tandem arrays , with their constituent monomers in different chromosomes of the same species may differ in the structure of I -row . Some general centromeric DNA sequence similarity found among primates , as well as in related species of higher plants . In grasses main component of the centromeric DNA of retroelements and copia gypsy family which tend to be dicotyledonous species are present in minor amounts.