Kaplan Nursing Entrance Practice Exam

An individual with a genotypic designation of XO is phenotypically what?

1. Male and fertile

2. Female and sterile

3. Male and sterile

4. Female and fertile

The correct answer is: Female and sterile

The genotype XO is commonly associated with Turner syndrome, which occurs due to the absence of one of the two X chromosomes typically found in females. Individuals with this genotype usually present as phenotypically female because they have the presence of female characteristics such as breast development, but they often experience a range of health issues, including infertility. The absence of the second sex chromosome can lead to the underdevelopment of the ovaries, resulting in a lack of menstrual periods and infertility. In contrast, the other options would not align with the characteristics of someone with the XO genotype. Males typically have an XY chromosome designation, and the presence of one X chromosome does not produce male physical traits or fertility.