sex linkage

(sex-linked inheritance) The tendency for a certain character to appear more often in one sex than the other.  It occurs because the gene controlling that character occurs on the same chromosome as the gene or genes involved in sex determination. Sex-linkage is seen in some dioecious plants, e.g. Silene album (white campion) in which the male is XY and the female XX, the Υ chromosome being considerably larger than the X.