Billy is a four-year-old boy. He has trouble walking and running like other children his age, and he sleeps through most of the day. He is diagnosed with multiple sclerosis. Billy's condition is the result of _____.
A) the abnormal lengths of the axons
B) a disruption in his myelin sheaths
C) the presence of an extra copy of chromosome 21
D) a disruption in his rapid eye movement sleep

Question

Quizplus · Accepted Answer

Multiple sclerosis is characterized by damage to the myelin sheaths, which are protective coverings around nerve fibers in the brain and spinal cord. This damage disrupts the normal flow of electrical impulses along the nerves, leading to the symptoms observed in Billy.

Billy Is a Four-Year-Old Boy