A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Xe Xi Xy

X chromosome

(Science: genetics)
A sex chromosome. In mammals paired in females (XX), in amphibia paired in males. The sex chromosome that is present in both sexes: singly in males and doubly in females; human females normally have two X chromosomes.One of the sex chromosomes found in both sexes. The X chromosome in males can express many dominant sex-linked traits because the shorter opposing Y-chromosome has no homologous genes to challenge the dominance of some genes on the Y chromosome. (biology-online.org)