In humans,sex determination is caused by:

If a character is always transmitted directly from a father to all his sons and from their sons to all their sons,then which chromosome carries the gene for the character?

$A$ couple has $6$ children-$5$ are girls and $1$ is boy. The percentage of having a girl on next time is (in $, \%$)

The number of autosomes in a human is (in $pairs$)

In higher unisexual animals,one pair of chromosomes is not identical in two sexes. It is called as . . . . . . .

The following diagram shows sex determination in honeybees. How many chromosomes do $P, Q,$ and $R$ have?
$\quad\quad P \quad Q \quad R$