Males have one Y chromosome and one X chromosome, while females have two X chromosomes.
If the father is affected by a genetic disorder, that means it will be passed down to only sons in the family, not females, since females do not have a Y chromosome.
This would mean the genetic disorder is Y-linked, and only on the Y chromosome, which is specific to males.
Although the diagram is not provided, I have encountered it before. The region labelled "B" is a ring with two small particles on it. This ring is the electron cloud and is where the electrons move. Therefore, it is negatively charged.
