$A$ female with $XXXX$ chromosomes will have the following number of Barr bodies:

Which one of the following disorders $CANNOT$ be treated by gene therapy?

$A$ chromosome complement with $2n-1$ is called as:

What would be the number of chromosomes in the ovum (fertilized by a normal sperm) that resulted in the appearance of Klinefelter's syndrome in the offspring?

$A$ disease caused by an autosomal primary non-disjunction is

Identify the given figure and select the correct option.
$\quad\quad\quad P\quad\quad Q$