According to the genic balance theory of sex determination in Drosophila proposed by Bridges,which $\frac{X}{A}$ ratio indicates a superfemale?

The sex of a human child is determined by:

$A$ family has five daughters and is expecting a sixth child. What is the probability of it being a boy?

$A$ male child will be born if:

In which of the following is the male monosomic $(XO)$?

The human embryo contains all the genetic instructions necessary to become either male or female. The male embryo contains a master regulatory gene that acts as a biological switch,turning other genes on and off. The absence of this gene results in a female,which remains sexually immature. This master regulatory gene is located on the .....