In Section 4.2, we considered characteristics encoded by genes located on the sex chromosomes (sex-linked traits) and how their inheritance differs from the inheritance of traits encoded by autosomal genes. X-linked traits, for example, are passed from father to daughter, but never from father to son, and Y-linked traits are passed from father to all sons. Here, we will examine additional influences of sex, including the effect of an individual’s sex on the expression of genes on autosomes, on characteristics determined by genes located in the cytoplasm, and on characteristics for which the genotype of only the maternal parent determines the phenotype of the offspring. Finally, we’ll look at situations in which the expression of genes on autosomes is affected by the sex of the parent from whom they are inherited.