What is the sex chromosome set for a typical human female?

• A. XX chromosomes
• B. XY chromosomes
• C. XO chromosomes
• D. YY chromosomes

Answer: (A)

Human sex is determined by the two sex chromosomes a person has. A typical human female carries two X chromosomes, written as XX, because she inherits one X from each parent and does not have a Y chromosome to trigger male development. The Y chromosome, which many associate with male traits, contains genes like SRY that steer development toward male characteristics when present. There are chromosomal variations, such as XO, where only one X is present (Turner syndrome) or XXY (Klinefelter syndrome), but these are not the common pattern for females. A YY combination isn’t viable in humans. So the common female sex chromosome set is XX.