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.
Mendelian traits in humans concerns how, in Mendelian inheritance, a child receiving a dominant allele from either parent will have the dominant form of the phenotypic trait or characteristic. Only those that received the recessive allele from both parents, known as zygosity, will have the recessive phenotype. Those that receive a dominant allele from one parent and a recessive allele from the other parent will have the dominant form of the trait. Purely Mendelian traits are a tiny minority of all traits, since most phenotypic traits exhibit incomplete dominance, codominance, and contributions from many genes.