Four boy have the same biological mother and father what percentage of each boys chromosomes come from the mother

The four boys should inherit X chromosome from their mother while the Y comes from their father. However, the X chromosomes typically have more genes than Y chromosomes. So, even if the mother or father equally contributes one X and one Y respectively, one is dominant over the other. In this case, it’s the X chromosomes — therefore, males have a fraction more of their mother’s traits.

The zone your looking for is the intertidal zone.