Final answer:
Wrapping hair too tightly around a perm rod can cause damage and breakage by putting excessive stress on the hair strands, particularly when chemicals are used to reform disulfide bonds.
Step-by-step explanation:
Wrapping the hair too tightly around the perm rod during the perm process can cause hair damage and breakage. This happens because the tension from the rod can stress the hair strands, potentially leading to the weakening of the hair's natural structure. When the hair is curled around the rod and chemicals are applied to disrupt and reform disulfide bonds, too much tension can exaggerate the effects of the chemicals and harm the integrity of the hair.
A perm, or permanent hairstyle, alters the hair's structure for months through a chemical reaction that reforms these bonds into curls or waves, but proper technique is crucial to avoid damage.