Loss of a single chromosome produces a condition called.

Broad palm with single palm crease is visible in a person suffering from-

What is the condition called when a human male develops breast tissue similar to that of a female?

In $Drosophila \text{ } melanogaster$, $3$ pairs of autosomes and sex chromosomes of $XO$ type give rise to a normal male in appearance. In humans, $22$ pairs of autosomes and $XO$ type of sex chromosomes result in:

In humans,mental retardation is associated with sex-linked abnormalities. It is generally due to:

The formation of multivalents at meiosis in a diploid organism is due to