Some proteins also help package DNA molecules into chromosomes. Recombination is a natural process that generates genetic diversity. Specific proteins are involved in recombination. The positions of the cuts can be measured and oriented relative to each other to form a crude map. The precise arrangement of these four subunits is used to transfer and sometimes store genetic information.
Somatic cells contain two pairs of each chromosome, while germ cells contain only one.
RNA polymerase is the enzyme that executes this conversion of information. As a result, females with X-linked disorders often have less severe symptoms than affected males. In contrast, because males have one X chromosome from the mother and one Y chromosome from the father, those who inherit an X-linked dominant disease trait typically fully express the mutated gene on the X chromosome, causing a more severe form of the disorder that may result in lethality before or shortly after birth. Fathers with an X-linked dominant trait transmit the gene to their daughters but not to their sons. Mothers with a single copy of an X-linked dominant gene have a 50 percent risk of transmitting the gene to their daughters as well as their sons.