If an X-linked mutation results in the absence of a certain protein, a cell which has inactivated the wild-type, X-chromosome will experience problems from the protein absence, possibly resulting in growth disadvantage of that cell, or even cell death, which will result in selection against mutant cells
DNA replication needs to occur because existing cells divide to produce new cells. ... So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!
Rosacea is the skin problem that causes the
reddening of the skin and dilation of the blood vessels on the face. If not
attended to, bumps and pimples develop. The nose in other cases enlarges as a
result of tissue build up.