Vacuoles are essentially sacs surrounded by a membrane. They are used by cells as temporary storage sites. They often store food, enzymes, and other materials needed by the cell, and some vacuoles store waste products.
The mutation will occur on the X chromosome. Males are more susceptible to sickle cell amenia because they only carry one X chromosome instead of two when compared to a set of female chromosomes. If a female only has the mutation on one chromosome the disease will not appear. However, when a male recieves the mutation on the X chromosome, the disease would appear, because they only have one X chromosome.