In biology, a gene is a sequence of DNA or RNA that codes for a molecule that has a function.
The melanocortin 1 receptor (MC1R), also known as melanocyte-stimulating hormone receptor (MSHR), melanin-activating peptide receptor, or melanotropin receptor, is a G protein–coupled receptor that binds to a class of pituitary peptide hormones known as the melanocortins, which include adrenocorticotropic hormone (ACTH) and the different forms of melanocyte-stimulating hormone (MSH).
Red hair (or ginger hair) occurs naturally in 1–2% of the human population.
A single-nucleotide polymorphism, often abbreviated to SNP (plural), is a variation in a single nucleotide that occurs at a specific position in the genome, where each variation is present to some appreciable degree within a population (e.g. > 1%).