In a majority of cases, Duchenne and Becker muscular dystrophy results from a
A. metabolic imbalance of the enzyme responsible for breaking down phenyl.
B. chromosomal structural deletion on the Y chromosome.
C. sex-linked inheritance of mutation from the mother.
D. neurological disorder caused by chemical imbalance in the brain.
my answer is c.
To determine the correct answer, let's break down each option and its relationship with Duchenne and Becker muscular dystrophy:
A. Metabolic imbalance of the enzyme responsible for breaking down phenyl: This choice is incorrect because Duchenne and Becker muscular dystrophy are not related to the breakdown of phenyl or metabolic imbalances involving this enzyme.
B. Chromosomal structural deletion on the Y chromosome: This choice is also incorrect because Duchenne and Becker muscular dystrophy are not caused by a structural deletion on the Y chromosome. Instead, they are caused by mutations in the dystrophin gene located on the X chromosome.
C. Sex-linked inheritance of mutation from the mother: This choice is correct. Duchenne and Becker muscular dystrophy are both inherited in an X-linked recessive manner, which means they are passed down from carrier mothers to their sons.
D. Neurological disorder caused by chemical imbalance in the brain: This choice is incorrect because Duchenne and Becker muscular dystrophy are primarily characterized as muscular dystrophies, which involve progressive muscle weakness and degeneration, rather than being primarily neurological disorders caused by chemical imbalances in the brain.
Therefore, the correct answer is C: Duchenne and Becker muscular dystrophy results from sex-linked inheritance, specifically from the mutation being inherited from the mother.