Addition (often signified by the plus symbol +) is one of the four elementary, mathematical operations of arithmetic, with the others being subtraction, multiplication and division. The addition of two whole numbers is the total amount of those quantities combined.hen addition is used together with other operations, the order of operations becomes important. In the standard order of operations, addition is a lower priority than exponentiation, nth roots, multiplication and division, but is given equal priority to subtraction.
Xeroderma pigmentosum is one of the inherited DNA repair disorders, which also include Cockayne syndrome, trichothiodystrophy, Bloom syndrome, RothmundâThomson syndrome, and Werner syndrome. It is inherited as an autosomal-recessive disorder and is characterized by a hypersensitivity of the skin to ultraviolet radiation, a deficiency in the repair of damaged DNA, and a resultant high incidence of skin cancers.
Huntington's disease is inherited in an autosomal dominant pattern. This means that everyone who inherits the faulty gene will eventually get the disease. A parent with a mutation in the HD gene has a 50 percent chance of passing the disease to their children.