Usually DNA, which is produced by RNA, which is produced by the nucleolus by creating proteins and those proteins create RNA which create DNA. its a whole cycle.
<span>Chromosomes, found in the cell nucleus, contain many genes. A gene is a section of </span>DNA<span>, which carries coding for a particular protein. Different genes control the development of different characteristics of an organism. Many genes are needed to carry all the genetic information for a whole organism.</span>