Customer Service is our #1 Priority! We take pride in providing services around the clock for U.S. citizens who need a passport fast. We provide this excellence in service by allowing you to access a passport specialist over the phone.
Male sperm cells in humans and other mammals are heterogametic and contain one of two types of sex chromosomes. They contain either an X chromosome or a Y chromosome. Female egg cells however, contain only the X sex chromosome and are therfore homogametic. The sperm cell determines the sex of an individual. If a sperm cell containing an X chromosome fertilizes an egg, the resulting zygote will be XX or female.
â¢ Mitochondrial DNA is smaller than nuclear DNA. â¢ Each mitochondrion contains thousands of mitochondrial DNA copies, but only a few copies of nuclear DNA exist in a human cell nucleus. â¢ Unlike nuclear DNA, all mitochondrial DNA comes from the mother and none comes from the father (maternally inherited).Nuclear DNA contains more information coming from both parents (both paternal and maternal).â¢ Unlike nuclear DNA, mitochondrial DNA can only be used to determine maternal lineage in an individual or a group, and it cannot be used to determine paternal lineage.â¢ Mitochondrial DNA may not be closely correlated to an individualâs fitness from other populations as nuclear DNA. Unlike nuclear DNA, all mitochondrial DNA comes from the mother and none comes from the father (maternally inherited). Nuclear DNA contains more information coming from both parents (both paternal and maternal).