There are 10 passport offices in the city of Phoenix where citizens of the United States can apply for a new passport. The majority of facilities are located at local post offices. An acceptance agent at these locations will receive your application form and supporting documents, administer an oath and witness the signing of the form.
backcross. in experimental genetics, union between a heterozygote of the first generation and one of its parents or an organism genetically identical to one of its parents. double backcross the mating between a double heterozygote and a homozygote.n experimental genetics, union between a heterozygote of the first generation and one of its parents or an organism genetically identical to one of its parents. double backcross the mating between a double heterozygote and a homozygote.
Miniature herringbone gears Image credit: Run Ryder | Perpendicular herringbone gears Image credit: Wikimedia | Crossed double helix gear Image credit: 1 DKM 2B. Herringbone gears, also called double helical gears, are gear sets designed to transmit power through parallel or, less commonly, perpendicular axes. The unique tooth structure of a herringbone gear consists of two adjoining, opposite helixes that appear in the shape of the letter 'V'.