Question

The genotype of a boy having sexual characters of a girl is
A. XXX
B. XXY
C. XO
D. XYY

Answer 1

Hint: The genotype shall decide the inherited potentials and limits of the organism from embryonic development to adulthood. Among the species which reproduce sexually, the genotype of an individual consists of the whole network of genes inherited from both parents.

Complete answer: The condition of a boy having sexual characteristics to that of a girl is due to the presence of that extra X chromosome, changing it as a 47, XXY karyotype. Children having this genetic condition seem to have no apparent noticeable symptoms, while some others may have varying forms of cognitive, social, psychological, and learning disabilities. Adults with Klinefelter syndrome might even have primary hypogonadism (decreased testosterone production), small and/or undescended testicles, bloated breast tissue, high posture, and/or failure to have genetic offspring. Some males with (47, XXY) are mosaic, meaning that only some cells have an extra copy of chromosome X and some cells will not have an extra X chromosome. Mosaic 47, XXY presumably due to a failure in the division of sex chromosomes in the fertilized egg after conception. Extra X chromosome generally results in primary testicular failure leading to androgen deficit. A tiny proportion of males with this disorder have been diagnosed clinically before birth. The syndrome can be established during gestation during a procedure to investigate foetal cells generated from amniocentesis or placenta for the next factor, including being older than the age of 35 or people with a family history of genetic problems.
So, the correct option is (B).

Note: This (47, XXY) genetic condition is not hereditary. Men with 47, XXY have one extra copy of the X chromosome owing to a non-disjunction error which develops spontaneously during sex chromosomes in the egg or sperm.