Karyotype of Klinefelter syndrome is-
**Core Concept**
Klinefelter syndrome is a chromosomal disorder characterized by the presence of an extra X chromosome in males, leading to an abnormal sex chromosome complement. This condition is associated with various physical and developmental abnormalities, including infertility, tall stature, and learning disabilities.
**Why the Correct Answer is Right**
The correct karyotype for Klinefelter syndrome is 47,XXY. This means that the individual has 47 chromosomes in total, with an additional X chromosome, resulting in a total of 2 X chromosomes and 1 Y chromosome. The presence of an extra X chromosome disrupts the normal balance of sex hormones, leading to an imbalance of testosterone and estrogen levels, which contributes to the development of physical and developmental abnormalities.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately represent the karyotype of Klinefelter syndrome. The correct karyotype is 47,XXY, not 47,XX.
**Option B:** This option is incorrect because it represents the typical karyotype of a normal male, which is 46,XY.
**Option C:** This option is incorrect because it represents the typical karyotype of a normal female, which is 46,XX.
**Clinical Pearl / High-Yield Fact**
Klinefelter syndrome is the most common sex chromosome disorder, affecting approximately 1 in 650 male births. Individuals with Klinefelter syndrome are at increased risk of developing certain medical conditions, including infertility, hypogonadism, and autoimmune disorders.
**Correct Answer: D. 47,XXY.**