Final Answer:
An individual that has only one X chromosome is genotypically XO. This person is phenotypically female.
Step-by-step explanation:
An individual with a genotype of XO, indicating the absence of a second sex chromosome (Y), is genotypically female. The sex chromosomes determine an individual's biological sex, with females typically having an XX genotype and males having an XY genotype. In the case of XO, lacking the Y chromosome, the individual follows the developmental pathway associated with females.
The presence of two X chromosomes (XX) is a characteristic of the typical female karyotype. However, in XO individuals, despite the absence of one X chromosome, the developmental process follows the female pathway. The single X chromosome provides the necessary genetic information for the development of female reproductive structures and secondary sexual characteristics.
Understanding the relationship between genotype and phenotype is essential in the field of genetics. While the genotype XO indicates a deviation from the typical XX female genotype, the phenotypic outcome remains female. This insight is crucial in comprehending the variations that can occur in the chromosomal makeup of individuals and the subsequent impact on their biological characteristics.