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.
Autosomal recessive or autorecessive is a mode of inheritance of genetic traits located on the autosomes (the 22 non-sex determining chromosomes). In opposition to autosomal dominant trait, a recessive trait only becomes phenotypically apparent when two copies of a gene (two alleles) are present.In other words, the subject is homozygous for the trait.n example to prove the point is sickle cell anemia. The genotype of sickle cell is caused by a single base pair change in the beta-globin gene: normal=GAG (glu), sickle=GTG (val). There are several phenotypes associated with the sickle genotype: -. 1  anemia (a recessive trait).