How many pairs of autosomes are present in Drosophila?

Which of the following correctly describes the mechanism of sex determination in the given example?

$A$ man affected by a certain disease marries a normal woman. They have $8$ children ($3$ daughters and $5$ sons). All the daughters suffer from their father's disease,but none of the sons are affected. What type of inheritance can you suggest for this disease?

Henking observed that in a few male insects,$50 \%$ of the sperm received a specific nuclear structure known as $X$-body,whereas the other $50 \%$ of sperms did not receive it. This method of sex determination was:

Assertion : In humans,the gamete contributed by the male determines whether the child produced will be male or female.
Reason : Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on $X-$ chromosome and some on $Y-$ chromosome.

There are five daughters and no son in a family. It may be due to