A pedigree is a diagram of family history drawn according to certain conventions. Males are depicted with squares, females with circles. Symbols for a mating pair are connected by a horizontal line, and the symbols for the offspring are attached to a horizontal line running underneath. The offspring are arranged from left to right in order of birth. For a given condition, open symbols indicate "not affected" and filled symbols indicate "affected." The status of an individual is indicated as that at the time the pedigree was compiled. In this example, the diagrams of the chromosomes also show the genotypes. The question marks in generation 3 mean that the genotypes of these individuals are unknown but could be determined by DNA typing.