The DNA in a person is a combination of the DNA from each of their parents. Part of an organism's DNA is  non-coding DNA  sequences. They do not code for protein sequences. Some noncoding DNA is transcribed into non-coding RNA molecules, such as transfer RNA, ribosomal RNA, and regulatory RNAs).Other sequences are not transcribed at all, or give rise to RNA of unknown function. The amount of non-coding DNA varies greatly among species.ome noncoding DNA is transcribed into non-coding RNA molecules, such as transfer RNA, ribosomal RNA, and regulatory RNAs). Other sequences are not transcribed at all, or give rise to RNA of unknown function. The amount of non-coding DNA varies greatly among species.