Final answer:
The genotype XXY corresponds to Klinefelter syndrome, a chromosomal disorder affecting males, with physical characteristics such as small testes and enlarged breasts. Turner syndrome, on the other hand, is an XO genotype that affects females.
Step-by-step explanation:
Klinefelter Syndrome and Chromosomal Disorders
The genotype XXY corresponds to Klinefelter syndrome. This is a chromosomal disorder that affects males, typically characterized by small testes, enlarged breasts, and reduced body hair. Unlike Turner syndrome, which is an XO genotype resulting in monosomy, or the presence of only one X chromosome in females, Klinefelter syndrome involves an additional X chromosome in males. In the context of chromosomal abnormalities, Down syndrome is classified by the presence of an extra chromosome 21 (trisomy 21), not by an abnormal sex chromosome count.
It is crucial to understand that Klinefelter syndrome results from nondisjunction during gamete formation, leading to a male with two X chromosomes and one Y chromosome. The extra X chromosome undergoes inactivation, which scientists can observe as Barr bodies within the nucleus of cells. Nevertheless, this inactivation does not eliminate the phenotypic effects of the extra chromosome, which is why individuals with Klinefelter syndrome may present with various physical and developmental attributes associated with the condition.