Which pair of chromosomes is concerned with Down's syndrome?

In Klinefelter's syndrome,what is generally the set of sex chromosomes?

Which one of the following genetic disorders is $CORRECTLY$ matched with its karyotype?

Which of the following statements are correct about Klinefelter's Syndrome?
$A$. This disorder was first described by Langdon Down $(1866)$.
$B$. Such an individual has overall masculine development. However,the feminine development is also expressed.
$C$. The affected individual is short statured.
$D$. Physical,psychomotor and mental development is retarded.
$E$. Such individuals are sterile.
Choose the correct answer from the options given below:

In which of the following disorders is the symptom of gynaecomastia seen in individuals?

The human chromosomes are divided into $7$ groups. $B$-chromosomes are: