How is Y-chromosome DNA different to DNA?
DNA (deoxyribonucleic acid) makes up our genetic material, and carries instructions for the biochemical processes of development and life. It comprises a double-stranded chain/sequence of c. 3,000,000,000 bases. Four types of bases are present in DNA, their chemical names are: adenine, cytosine, guanine and thymine. Y-Chromosome DNA has several unique features: The presence of a Y-Chromosome causes maleness. This little chromosome, about 2% of a father’s genetic contribution to his sons, programs the early embryo to develop as a male. It is transmitted from fathers only to their sons. Most of the Y-Chromosome is inherited as an integral unit passed without alteration from father to sons, and to their sons, and so on, unaffected by exchange or any other influence of the X-Chromosome that came from the mother. It is the only nuclear chromosome that escapes the continual reshuffling of parental genes during the process of sex cell production.
