The W chromosome represents the female sex chromosome, however, it may be referred to using a variety of synonyms. One of the most common is the female chromosome, as it is responsible for determining the biological sex of females. Other synonyms for the W chromosome include the double X chromosome, as females typically have two X chromosomes (XX), with one of them being the W chromosome. Another phrase used for the W chromosome is the egg chromosome, highlighting its involvement in the process of producing eggs for reproduction. Despite having different names, the W chromosome or female sex chromosome has long been studied for its role in biological sex determination and certain medical conditions.